Firstly,reduce your problem. Get rid of one of your projectors you have too many.( my address is .... )
There is two basic ways that I see to solve your problem. Both will work.
1) Make a copy of the movies skin, say myothermovies. For each screen associated wth what I would call a DVD database/catagory ( in DB file there is a metatag type=movie)
you can specify individual launch commands when you want to play any item. The copy of the screen needs to change the category name to myothermoviescat and associate your movies database with this category.
Now have a global.exe associated with this screen OR, in a40exp5 and above, you can specify your own event to to execute any desired exe and pass it the name of the file to play as a parameter using the syntax that is given in exp5,but replacing movies category with your new category, like this %myothermoviescat>parameter%. This is now your new command to associate with a PLAY event. Complex to read, simple to do.
2) Another general trick is to have a programme sit between xlobby and the DVD player and depeding on passed parameters take different actions, i,e called any DVD programme with specific parameters. Instead of calling DVD player direct you call the "middleman"- typical integration trick in computing. This in turns does some processing/calls other programmes to complete the job. AKA simple mans "plugin "
I use this technique to have a single screen/database with different AVI types. Depending on the file extension I can call up up any Player or Whatever at will.
Such "middleman" programme to do exactly this can by found at (
http://www.myhtpc.net) called myOMP or MySP or write your own. They work standalone, there also allow you to see what xlobby sends out on the calling command line for debugging purposes.
Actually HTPC front ends should be able to do this themsleves,but that is another thing for the to do lists.