Thanks for the quick reply. I understand about 90% of what ur saying. The only part im not sure on is when I put in the formula, do I have to do each cell by hand? ="X-" & A2, ="X-" & A3, ="X-" & A4...etc?? Or can I just highlight my helper column and use some kind of formula that covers cells A2 to A6005 (thats how many cells there are!).
That means that if you copy Z2, and paste it in say, Z5, Z5 will contain A5.
By the way, you can also "paste down" a formula by selecting Z2, putting your mouse over the lower right corner until you see a 'handle', clicking and holding while dragging downward as far as you need. (that is how I would do it).
By the way, if you had ="X-" & A$2 and did the same thing, you would get the same value in every cell.
So, in Z2,
Enter:="X-" & A2
Now highlight, and look for the 'handle' in the lower right corner.
Drag it down 6000 rows or however far you need.