metapost and filenames containing tilde (~)

I started this discussion on comp.text.tex but since it seems to be (only?) 
an fpTeX problem I'm transferring it here...

Using the current fpTeX (TL2003 +updates) mpost.exe chokes on filenames 
containing tilde such as

  C:\DOCUME~1\PETERD~1\LOCALS~1\Temp\myfilename.mp

This breaks the perl script purifyeps which uses the %TEMP% 
directory.  Microsoft in their infinite stupidity now uses horrible paths 
like the one above as the default for  TEMP and TMP.


For the whole thread including comments from Scott Pakin and Dan Luecking 
please see:

http://tinyurl.com/3blql

or Google "purifyeps workarounds :comp.text.tex"

Thanks,


--
Peter Denisevich
Fairfax, California