Help! Do not change the value if one is already there

[cjunk20]

I have a cell that changes its value periodically but that cell is used in a formula each month. How do I keep the formula results for the previous months when the cell values changes. Here is a SUPER simplified example:
a1=2 and b1=3
c1="January" c2=a1+b1 (which equals 5)
d1="February" d2=a1+b1 (which equals 5)
e1="March" and so on. In March, a1 changes to =5 so, e1=a1+b1 (which now equals 8)

Now a1 and b1 already have formulas in them to calulate a value and they are fairly complex.
What I want to know is how can I keep c2 and d2 to remain at 5?

More about my actual document:

I am planning on sending this for others to use and, I don't want them to need to alter it.

My A1 figures what "phase" some one is in (1,2a,2b,3,4, and 5)
then B2 will figure how many items a person must do (the are 5 different items) according to "male or femal and age".
It was much more intensive than I thought it would be but, because I had 3 things to look at, I couldn't use a chart for lookups until I figured A1.
Now, A1 will change as a person progresses to the next phase and B1 changes as age changes.
These values are returned to another area where the actual #'s are also recorded (on the row below it). The #s are compared and if they accomplished thier tasks, which is a formula because it's 2/3 and 1/2 out of the 5, it records a "Pass" if not it records a "Retest". This is all done 1/month.
As the "phase and Age" change the test is harder so, if it goes back when I change A1 and recalculates the months that have already been scored, it could mess up everything.

 

[GK039]

How many times such a change mid year will probably happen?

I have a cell that changes its value periodically but that cell is used in a formula each month. How do I keep the formula results for the previous months when the cell values changes. Here is a SUPER simplified example:
a1=2 and b1=3
c1="January" c2=a1+b1 (which equals 5)
d1="February" d2=a1+b1 (which equals 5)
e1="March" and so on. In March, a1 changes to =5 so, e1=a1+b1 (which now equals 8)

Now a1 and b1 already have formulas in them to calulate a value and they are fairly complex.
What I want to know is how can I keep c2 and d2 to remain at 5?

More about my actual document:

I am planning on sending this for others to use and, I don't want them to need to alter it.

My A1 figures what "phase" some one is in (1,2a,2b,3,4, and 5)
then B2 will figure how many items a person must do (the are 5 different items) according to "male or femal and age".
It was much more intensive than I thought it would be but, because I had 3 things to look at, I couldn't use a chart for lookups until I figured A1.
Now, A1 will change as a person progresses to the next phase and B1 changes as age changes.
These values are returned to another area where the actual #'s are also recorded (on the row below it). The #s are compared and if they accomplished thier tasks, which is a formula because it's 2/3 and 1/2 out of the 5, it records a "Pass" if not it records a "Retest". This is all done 1/month.
As the "phase and Age" change the test is harder so, if it goes back when I change A1 and recalculates the months that have already been scored, it could mess up everything.

 

[cjunk20]

Currently, I have 30 sheets (1/person), which will increase as a person joins our organization.

Each person's chart can change up to 6 times a year.

 

[GK039]

For six times a year you will need a UDF. I can give you a formula for one change though, but i don't think it will be the solution you are looking for

Currently, I have 30 sheets (1/person), which will increase as a person joins our organization.

Each person's chart can change up to 6 times a year.

 

[cjunk20]

Well, I'm getting desperate. No one has been able to give me a solution that will work yet. The copy and paste special thing would have to be done everytime something changes. I want to put it in and leave it alone. It seems like there has to be a was to "freeze" a cell once it hs a value but, I have had no luck. I'm not stupid but, I am not very experienced either. I have figured out amazing things thus far and have to say I'm pretty proud of myself. Everytime I think I'm done I seem to find one more thing to fix. hahahaha I just realized today that it would likely change all the previous testing results once a new value is put in. I'm pulling my hair out on this one.

If you could send me the formula, I'd appreciate it. I have no idea what a UDF is but, I can tell if it will work by looking at it.

Thanks

 

[GK039]

A1 = your first value (2 in your example)
B1 = your second value (3 in your example)
I used E2 to P2 for months January to December.
In D2 place a data validation list with the months
In cell D4 type whatever you like just to indicate that in row 4 you will place the new values. E4 to P4 will house the new values by month
Formula in E5 copied up to P5

=IF(MATCH($D$2,$E$2:$P$2,0)>COLUMNS($E4:E4),$A$1+$B$1,SUM($B$1,INDEX($E$4:$P$4,,MATCH($D$2,$E$2:$P$2,0))))

When you choose a month from the drop down list, eg: August and you have put a new value to cell L4 (new value for August for example 15) then all cells up to August will add up to 5 whereas August to December will add up to 18

As told you before, unfortunately it can help you only for one month. You have to use VBA for six months

Well, I'm getting desperate. No one has been able to give me a solution that will work yet. The copy and paste special thing would have to be done everytime something changes. I want to put it in and leave it alone. It seems like there has to be a was to "freeze" a cell once it hs a value but, I have had no luck. I'm not stupid but, I am not very experienced either. I have figured out amazing things thus far and have to say I'm pretty proud of myself. Everytime I think I'm done I seem to find one more thing to fix. hahahaha I just realized today that it would likely change all the previous testing results once a new value is put in. I'm pulling my hair out on this one.

If you could send me the formula, I'd appreciate it. I have no idea what a UDF is but, I can tell if it will work by looking at it.

Thanks

 

[cjunk20]

I'm not sure if that is what I'm going to do or not. It does give some things to look at and consider. I may just have to resort to changing the sheet a little, again. I do appreciate the help though. Thanks