I need to set up a formula that will allow me to specify a specific
workbook and worksheet name as part of a relative reference.

I can refer to a cell on a specific sheet within a specific workbook
using:

=[Book.xls]Sheet1!A1

I can accomplish the same thing using:

=INDIRECT(CONCATENATE("'[",$X$1,"]",$X$2,"'!",”A1”))

Whe
Cell X1 – Book1.xls
Cell X2 – Sheet1

If I copy/paste the first expression ‘A1’ will behave as a relative
reference however the second expression is effectively:

=[Book.xls]Sheet1!$A$1

Is there any way I can define the formula with the workbook and
worksheet names defined in the specified cells, X1 and X2 in the
example, and still have the ‘A1’ portion behave as a relative
reference?

Thanks,
Russ D.