sundiro50: Well, i had never heard of a .mat extension so i looked it up

There are 3 different types, so i guess it would be handy to know which one we are dealing with.

The most common one is a Microsoft one (Microsoft Access Table = MAT), and to open it you need Microsoft Access. You can download a free 60day trial of it, BUT it should be part of Microsoft Office (do not know about 2003 version).

Look HERE to see other .mat extensions