First, I believe that you need Crystal V8.5 to get the DLL for PDF export. For V8.0, you had to get it from Crystal directly (it wasn't in the V8 distribution).
This example is VB / RDC. Sorry, but I don't know Delphi.
Dim Report1 As CrystalReport1 'name of your RDC report
Dim crystalExportOptions As ExportOptions
Set crystalExportOptions = Report1.ExportOptions
crystalExportOptions.DestinationType = crEDTDiskFile
crystalExportOptions.DiskFileName = "youroutfilename" crystalExportOptions.FormatType = crEFTPortableDocFormat
Report1.Export False Brian J. Alves
Terrier Consulting, Inc.
Email: brian.alves@worldnet.att.net
VB / Crystal / SQLServer
(Currently available for consulting in Chicago)