Gui's for dos applications

How do I call a dos program from witin a vb program?

I have several dos programs that use the standard format eg [dos.exe] [filename] [switch]

What I would like to do is specify the filename and switch then execute the command.

I know this is a very simple problem but i can't find any referance to it anywhere.

I am quite new to vb but not to basic. I used to write alot of stuff in basic on old 8 bit machines and the syntax is very simlair.

Thanks Bob