Alrighty here...

I have a short little function that tells me the value of the first available row. IE if my sheet looks like this:

...A B C D E
1 X
2 X
3 X
4
5

It will return the number 4 because 4 is the first available number in the column that is blank. The formula looks like this:

Formula: copy to clipboard 
=MATCH(TRUE,INDEX(ISBLANK(A1:A100),0,0),0)


So that works up and down... What if I want the letter of the first available column from left to right, whereas the above example would return the letter B? Is that possible?

Basically if I changed the code to:

Formula: copy to clipboard 
=MATCH(TRUE,INDEX(ISBLANK(A1:AX1),0,0),0)


It would display a B (or C if B was filled, etc)...