I need to use a value from a cell to buil a refernce to a cell in another
workbook. I've mostly figured out how to do it using INDIRECT but have hit
one snag.

Current:
=INDIRECT("[ProgressUpdate_"&$D$3&".xls]"&$D$3&"!D6")

where $D$3 contains the value to use in building the reference and D6 is the
cell in the other workbook that I need returned.

But, as I copy this formula down subsequent rows, I need the returned cell
to move down relatively. i.e If the above formula is in row 1 in the local
workbook and returns cell D6, when copy the formula to row 2 I need it to
return cell D7.

How can I do this?

Thanks in advance.