i am trying to use indirect to look up another workbook to see whether or not
the cell is blank and hence the ISBLANK. This formula works but i can not
fill it across or down as this cell (D5) remains constant.

IF(ISBLANK(INDIRECT("'["&$A$3&" "&$I$1&".xls]other'!D5")),sheet1!D4,"")

any ideas?