Help with Crystal Report from Store Procedure

Hi to everyone, I have a problem and I not found a solution, I have a report create with crystal the report the datasource is a store procedure but this SP has a parameter @PartnerID varchar(20).   My problem is that the parameter appears like a textedit on parameter box but I need to show a combo list of all Partners but I cant modify this parameter.  I try to hide and create new one but now appears 2 parameters.  

Exist some way to hide the parameter from the SP and only show my custom parameter

Thanks for you help..