Hi,

I have a number of formulas referring to certain data sheets (named as per
week) like this one..:
=IF(ISNA(VLOOKUP($A2,wk19!$A:$O,2,FALSE)),"",VLOOK UP($A2,wk19!$A:$O,2,FALSE))

The maintenance of the worksheet would be easier if I had those wk19, wk20,
wk21, ... as a header row in the data table and refer to those cells in the
formula, but how do I achieve that?

wk19!$A:$O should be something that.:
1' reads the value from cell D1 and
2' combines that with a string !$A:$O

Then I could just copy the formula to the next column and it finds the
corresponding week ID from cell E1. Might be easy, but I just can't find it.

Thanks,
Jouni