>>Extend the list... you asked how, and I gave an example of syntax.
>>
>>You can list multiple extensions -
>>?GETFILE("excel linen:xls,xlsx,xlt;in a word, ID:doc,dot,docx;powerplant perfectation:ppt","Gimme some","open up")
>>
>>As to what... I don't know all the extensions, and that's more in the "what" part of the question, which is, I guess, your homework.
>
>That's the thing - I'm wondering if there is other way to get all the possible document extensions. I don't know about drawing extensions either - don't have such files at home.

Гугл с тобой знает все...