I'm not sure I understand exactly what you need. However,
let's say you want to pull row 1 from your "Data Sheet"
data. If you put a one in Cell A1, the following formula
would pull the value in A1 from the Data Sheet.

=OFFSET('Data Sheet'!$A$1,0,'Report Sheet'!$A1-1)

Conversely, if you just put the words "Data Sheet" in cell
A1, the following would use that to pull in the contents
of A1 from the Data Sheet:

=OFFSET(INDIRECT("'"&A$1&"'!$A$1"),0,0)

I hope that helps or at least gives you some direction.

Eric