Predator, you can't directly edit QVM files, those are compiled Quake Virtual Machine files which contains bytecode (a slightly higher level than machine code). You need the Quake 3 SDK to modify and alter Quake 3, and then compile the modified files with the ID compiler (a modified LCC compiler) supplied in this same SDK package.

Although, if I am correct (though I haven't checked deeply), the UI part of Excessive Plus has not been touched, so if you recompiled with a few modifications and included the file (ui.qvm) into the Excessive Plus folder under the vm directory, it would work, though you wouldn't be pure anymore.