VB Code or not to meet several requirement maybe Message Boxes

[RLPeloquin]

I've backed myself in a corner with this spreadsheet. The formulas in cells C10 - N10. These cells automatically pick up previous "Meter Readings" which works great. But... the Initial "Meter Reading" can fall on different months. So... for example if the Initial "Meter Reading" say falls in "April" how would I put that reading in Cell "F10" without affecting the other formulas in C10 - N10. I'm thinking a VBA code that would Unprotect Sheet, Recognize the "Initial Start Month" maybe by a "Message Box" that a "Month" could be entered into and another "Message Box" for the "Initial Meter Reading" entered into, then put "Initial Meter Reading in Cell "F10". "Then Protect Sheet once entered. Any help greatly appreciated!

Generic Electricity Usage.xlsx
	A	B	C	D	E	F	G	H	I	J	K	L	M	N
1	Site 1										Your Company Name
2	Name:										Your Address
3	Street Address:										Your City, State & Zip Code
4	City:			State Abbr:		Zip code:
5	Phone:
6	Email:						Date of Meter Reading
7
8			January	February	March	April	May	June	July	August	September	October	November	December
9	METER READING
10	PREVIOUS MONTH
11	KWH USED
12	RATE	0.12
13	YOUR ENERGY USEAGE FOR:
14			January	February	March	April	May	June	July	August	September	October	November	December
15	KWH
16	TOTAL
17	AMOUNT PAID
18	BALANCE DUE
19
20	DEPOSIT (IF ANY)			Note about Deposit:
21	Method of Payment			Amount Paid				Amount Due
22				January				January
23				February				February
24				March				March
25				April				April
26				May				May
27				June				June
28				July				July
29				August				August
30				September				September
31				October				October
32				November				November
33				December				December
34
35
36			Total Payments				Total Charges
37
38				YOU HAVE A CREDIT OF:
Site 1

Cell Formulas
Range	Formula
C10	C10	=IF(N10="","",N9)
D10:N10	D10	=IF(D9="","",C9)
C11:N11	C11	=IF(C9="","",C9-C10)
C15:N15	C15	=IF(C9="","",C11)
C16	C16	=IF(C15="","",C15*B12)
D16	D16	=IF(D15="","",D15*B12)
E16	E16	=IF(E15="","",E15*B12)
F16	F16	=IF(F15="","",F15*B12)
G16	G16	=IF(G15="","",G15*B12)
H16	H16	=IF(H15="","",H15*B12)
I16	I16	=IF(I15="","",I15*B12)
J16	J16	=IF(J15="","",J15*B12)
K16	K16	=IF(K15="","",K15*B12)
L16	L16	=IF(L15="","",L15*B12)
M16	M16	=IF(M15="","",M15*B12)
N16	N16	=IF(N15="","",N15*B12)
C18:N18	C18	=IF(C15="","",C16-C17)
E22	E22	=C17
E23	E23	=D17
E24	E24	=E17
E25	E25	=F17
E26	E26	=G17
E27	E27	=H17
E28	E28	=I17
E29	E29	=J17
E30	E30	=K17
E31	E31	=L17
E32	E32	=M17
E33	E33	=N17
I22	I22	=C18
I23	I23	=D18
I24	I24	=E18
I25	I25	=F18
I26	I26	=G18
I27	I27	=H18
I28	I28	=I18
I29	I29	=J18
I30	I30	=K18
I31	I31	=L18
I32	I32	=M18
I33	I33	=N18
E36	E36	=SUM(E22:E33)+C20
I36	I36	=SUM(C16:N16)
D38	D38	=IF(I36>E36,"YOU OWE:","YOU HAVE A CREDIT OF:")
G38	G38	=E36-I36

 

[RoryA]

This appears to be a duplicate of this. Please don't post the same question more than once.