Subscript out of range when calling crystal report from Delphi VCL version 5.5.1

I deploy multiple versions of reports to my customers.  Some of the reports will require certain parameters and others won't.  Here's my problem.  If I add a parameter to one report, I have to add it to all versions of the report regardless of whether they use it.  If I don't and try to run a report using a report source file that doesn't contain it I get Error:116 Subscript out of range :: ParamFields[ paramfield number].  I understand why this is happening, but is there any way I can get around it.  (i.e. if the parameter doesn't exists, just ignore it)

I'm using Crystal 8.5,  Delphi 5 and Delphi VCL version 5.5.1