Start / Stop - running process/service - batch files

Hey guys, I need to throw a couple of batch files together for a 2k server to stop the Nav for Exchange service so that the mail can be backed up by the tape backup. Once its backed up, I need to start it up again. The Backup software can call .bat files before and after backups, so I'd like to keep it simple with good old fashioned commands. Can anyone point me to a pre made reference? I was never that strong on commands and I'm too busy to research right now - this is due tomorrow.

Cheers.

You can start, pause and stop any Windows service by using;

NET START\PAUSE\STOP ServiceName

at the Command Prompt.