Hoster will not read or convert MCG files. I believe it's a proprietary format so I doubt MTU has the legal ability (I'm not trying to speak for MTU - this is just a guess).
You can download and save the shipping charge however you'll have to wait for MTU to email you a download link and other important info (usually less than 24 hours)
ADMIN NOTE: NOT QUITE RIGHT. 
If you order by Credit Card, our web store script sends the download instruction email within 10 seconds of receiving approval on your card. It may take longer to get to you, but MTU performs intstantly! 
You need to be online (or have a floppy disk drive and access to a computer online) to activate the software - you can activate it on 2 machines, the license is 1 machine for your show and 1 for backup. If you have 2 shows simultaneously it's expected you'll purchase 2 licenses (plus a second set of original cd+g's of course).
And it's always a good idea to have your music backed up on an external HD.
Sam