I was reading a thread concerning the OFFSET & INDIRECT functions. I need it to reference a another workbook. I wrote in the formula like the one on the thread and instead of refering to the worksheet in the current workbook, I referenced the other worksheet and workbook. I am getting a REF# back what am I doing wrong or am I able to reference a different workbook. An example of the formula is below. I need to find a way to reference the other workbook and worksheet.

=IF(OFFSET(INDIRECT("Sheet1!A1"),ROW()-1,COLUMN()-1)=0,"",OFFSET(INDIRECT("Sheet1!A1"),ROW()-1,COLUMN()-1))