Romlister is ok, but all it does is list the available roms in that version of mame, not the roms I actually have on my machine -
Oops. Sorry about that. Well while not very elegant, a down and dirty method would be to use romlister to first create a csv file of all rom names and descriptions. You could then create a text file with just your rom names from the command prompt using
dir /b > roms.txt
You could then pull these two sets of data into either MS Access or Excel and list only the rom descriptions of the roms that you possess. In other words query the data from the csv file based upon each name in roms.txt using a function to leave off the zip extension such as (in Excel):
LEFT(rom_name,FIND(".",rom_name)-1)
In Excel, you could use a vlookup function to grab the rom description or in Access just a query after importing the files into two separate tables.