I haven't used it but you should be able to use logiqx's Datutil to convert the clrmame dat to a romcenter dat. Grab it at
www.logiqx.comLiQuiD8
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It is possible to convert dats between ClrMamePro and RomCenter with ease. The
most simple way to convert from one format to the other is like this:
datutil <datfile>
This will convert a ClrMamePro dat (listinfo) to a RomCenter datafile or
a RomCenter datafile to a ClrMamePro dat. The new dat is called 'datutil.dat'.
If you want to specify a different output filename, use the '-o' option.
e.g. datutil -o clrmame.dat romcenter.dat
This would convert romcenter.dat, saving the new file as clrmame.dat.
There is also a '-a' option to append to an existing file. This is especially
useful when converting/extracting individual games (explained later).