It IS possible to run specific Crystal Reports from JDE - say as a Row exit in Customer Service Inquiry and you pass a Sales Order # to the report as a parameter.
One way for fat clients is to wrap the Crystal runtime report viewer in VB or C# code or whatever you're comfortable with as a programming language. Your code can then take the SO# as a command line argument and pass it to the Crystal Report Viewer object. In E1 your Row Exit code would need to use the BSFN that lets you execute/run an external program - which would be the name of your little custom program. Net, net it can be done (we do it here) but you'll have to do some coding first.