[Wine] drive mapping

[ron r]

Hello.  I am a new user of wine.  I boot from a linux drive and have a second HD, which can run windows xp, as the secondary master.
I eventually got my windows program to run with wine, but the drive/partition that it is on is considered to be drive F: by wine.   The program tries to read files from drive C:\xxx and can't find them because that drive is now considered to be "F:".   (I think that's why - because that program runs just fine in windows.)
Also, I had to copy a .ocx and .dll file from c:\windows\system32\ folder to the folder the program is in, so it will even run.   Before I did that, wine would say it can't find the needed files in  c:\windows\system32\, even though the files are there.   I think it is because wine thinks it is F: drive and not C:.
I thought that the config form would let me assign that drive/partition to a particular drive letter, like "C:", but I doubt that now that I've tried to use it. 

Am I misunderstanding something?   Is there a solution?
Thanks for any replies.