Indirect alternatives
 

Using XL 2007 with 2003 compatibility

The below equation works - but are there better alternatives?

=INDIRECT(Model_info!$E$25&"!R"&ROW()&"C"&COLUMN() ,FALSE)
There are several sheets that are date driven, that the format is the same
but the numbers on the sheets are different. The "assumptions" sheet then is
used to run the model. The date entered by the user will determine which
sheet to grab the values from.