=INDIRECT("'[Direct FTC Tracking 2009.xls]"&R2C2&"'!R81C3",FALSE)

This is the formula I am trying to use. What I am trying to accomplish is
to return the value of Cell (R81C3) on variable Sheet (R2C2), in the
workbook [Direct FTC Tracking 2009.xls]

(Sheets are monthly and the reference of R2C2 is the current sheet date
reference, which exactly matches the name of the sheets from the workbook
[Direct FTC Tracking 2009.xls])

The formula returns #REF!

Before I went to R1C1 style (for ease of VBA use) this formula worked like a
charm and looked like this

=INDIRECT("'[Direct FTC Tracking 2009.xls]"&$a$2&"'!$c$83",FALSE)