Crystal Reports exporting CR to pdf with a set path

Message

   I have tried a few things, but alway get an invalid file path error.. 

I have backed off from my complex path to just get it to store on the c:\
drive rather then some local folder under my username.
 It seems if I ask for any path it get upset...

rptname = "testrpt"
strRptPath = "c:\" + rptName

crSet.CrystalRpt.FileName = strRptPath
crSet.CrystalRpt.ExportToDisk(ExportFormatType.PortableDocFormat, rptName)

'crSet.CrystalRpt.ExportToHttpResponse(ExportFormatType.PortableDocFormat, Response, True, rptName)
Commented out field is where I really want to set the path, so if logic is different in that from my attempt to make it simpler, please let me know..

(Oh I did try to put path right on the .export____ --- But they changed als "\" to "_" which really made the path invalid. At least .filename left all the "\" alone.)

Any way to get Crystal to let me choose the path???