I think I've got it! Here's the code for anyone else who might need it (I'm using CR10, VFP8 and Fox2X tables):

loCR=CREATEOBJECT("CrystalRuntime.Application")
loRpt=loCR.OpenReport("MyReport.rpt")

IF loRpt.HasSavedData
   loRpt.DiscardSavedData()
ENDIF
FOR EACH loTable IN loRpt.Database.Tables
   loTable.Location=FORCEPATH(loTable.Location,"c:\MyPath\")+".dbf"
ENDFOR
FOR EACH loSection IN loRpt.Sections
   FOR EACH loObject IN loSection.ReportObjects
      IF loObject.Kind=5 && Subreport
         loSub=loRpt.OpenSubreport(loObject.SubReportName)
         IF loSub.HasSavedData
            loSub.DiscardSavedData()
         ENDIF
         FOR EACH loTable IN loSub.Database.Tables
            loTable.Location=FORCEPATH(loTable.Location,"c:\MyPath\")+".dbf"
         ENDFOR
      ENDIF
   ENDFOR
ENDFOR

>That's what I'm trying to do, but I can't seem to find the collection of subreports. I can open a specific subreport once I have a name, but I can't see how to get them through the collection.
>
>>There is a subreports collection on the main report. Drill down through each one, setting it's properties just as you would with the main report.
>>
>>>This has been helpful, but how do I drill down to the tables of each subreport?
>>>