Does anyone know if a program exists to change an inventor/cad file to 3d studio format? I only ask this, because I only use 3d studio, and dont want to bother getting inventor or cad and doing it through there 
All those posts involve having both Inventor and 3d Studio, which I do not.
You’ll need some sort of convertion tool. I suggest you seach google for it, but doubt you will find anything as Inventor does not use an open standard filetype.
Your best bet is to get someone to translate the inventor files into some sort of exchange format for you to import into 3d MAX.
Greg
Inventor has a plugin designed to specifically do this - to Max 5. Unfortunately the update to Max 6 seems to not be available. I have read many posts on different forums on the topic. You might try a plugin from nPower Software called Power Translators. There is a demo download but I have yet to try it. Worth a chance though. I have heard good things about this company.