GENERAL Report WebService for Crystal Report

Question

Dear Sir/Madam, I've a problem to use the Crystal Report to get Reports by WebService in Windows Forms. I can add a Webservice to a Report in a n-Tier Application but this webservice assigned to a particular Report. I need a GENERAL Report webservice to get ReportName as a parameter and retreive specified Report. Explain with an example will be appreciated. Best Regrads, Mehdi.