[Zope] Unpack, "You are not allowed to use unpack..."

Hello Zopistas.... I'm trying to read a binary file from within zope... It's format is rather simple, but it does a length stored as an Unsigned long. In a test program, I used to struct.unpack(...) to read in the unsigned long... Unfortunatetly, Zope don't want me to do this 8-( Is there a work around? Is there a work around, or must I create an unpack(..) external script just to get this value? Jerry Westrick...