[Dubious]

Lemmy, if you really want to program something consider a program to allow the modders to produce a "difference" file with just their changes to the standard files. What we need is a program which would take that 'diff' file and allow the 'non-modder' player to merge the difference file with the existing file in the 'modpath' directory. This would allow several independent mods to be merged together.

While simple in theory, this is quite complex because many mods alter a number of files to different degrees and all the changes are needed for it to work together correctly the way the author intended. What's probably needed is a multi-pass approach to identify what (in general terms) gets modified and then whether the file or specific parameter has already been modified from that distributed with the game. Then an option to merge the changes wholesale or piecemeal. Whenever presented with a dilemma as to what to do, offer the user a choice.

Or you can take a look at some of the mod tools which are already in the modding archive and work on something which is missing. Zeno42 is the most active in this area as I recall.