Kams Gmax script Problem

Please Anybody help me.Currently I am using GMAX 1.2 and Kams dff script to import gta san andreas models.I imported some car but when I select dff file it says "No standard dff file" and I tried to open cars of gta3 but there was no problem now I renamed and attached all file and when I was readey to export I selected collision file and clicked on export now I gave it name same as original model and clicked on save but it replayed me "Runtime
Error: Feature Unavailable "fopen write mode" I tried skipping col and other every option but same ans. I am from poor country and cannot download 3ds max nor buy because both are unavilable here.So please somebody post solution or tortional for my both above's problem and sorry for my bad english.