http://www.google.co.uk/search?q=how+to+make+a+batch+file
It's more complex than that; ASSetTitle has to be run significantly after Audiosurf is started, otherwise it won't link.
I stopped supporting/updating it because it suited my needs and I assumed nobody else was using it. I didn't realize there were other people using it. I'll try to fix it so it will always link, even if it's started before. I'll also get to work on doing a tray icon. Maybe even an autolaunch
Okay, I have fixed the code so that it will now link, no matter what order things are started in. As far as I see it, you have two options:
1) Make a batch file, as they recommended. (RECOMMENDED)
2) Have ASSetTitle run on startup. (Not recommended, but probably easier for a non-technical person. ASSetTitle only consumes 2 mb of RAM in idle, so it's not that bad.)
get the latest exe and as.cfg here:
http://code.google.com/p/assettitle/source/browse/#svn/trunk/Release