What about something like:
Case ( Get ( CurrentDate ) - DonationDate > 365; Substitute ( DollarAmount; [0; *]; [1; *]; [2; *]; ... [9; *]); DonationDate )
Assuming, of course, that you still want them to know how many digits were in the number (just not the actual amount). If you don't want that, then just fill in the center part with "Hidden".
Hope that helps.
Wow, quick response. Thanks I'll try that. I actually need different symbols for different amounts, but I think I see how that would work too.
Thanks for your help jsalzer. This is what I came up with. There is probably a more elegant solution, but it works.
Case (PldgeAmt>51; "$";
PledgeAmt > (50) and PledgeAmt < (101);"$$";
PledgeAmt > 500; "$$$$$$"