A way to run applications by extension/remember default applications?

[Andreas Jantvik Gyllenlid]

Hello, 

I was wondering if it is possible to configure MC to run certain applications with specific applications.
I do not know how MC runs things at all.

With MPG files Mplayer just fires out automagically when I just <enter> the file. When trying to run an m2v file, Mplayer doesn't run, MC spits out: 

bash: ./a.good.music.video.m2v: cannot execute binary file

I can press F2 and "Do something ..." and just type mplayer, and it works.. And I can type mplayer C-<enter> in the command line below.

How do I make MC do this automatically for me?
For example I also want iso-files to be run with vlc per default. Is there something like Gentoo's config somewhere?

Thanks!