If what you want is to use the TRANSFAC with GCG, there is solution
somewhat different from what you first had in mind :
at ftp://ftp.gbf-braunschweig.de/pub/transfac/gcg you will find
the TRANSFAC in the form of GCG pattern files that are taken as
input by "map" or "findpatterns". You must start the program with
parameter -data=xxx where xxx is the name of the file.
At the BEN site, we have installed a file transfac.dat with the
complete TRANSFAC in "GenMoreData" as an alternative to tfsites.dat
It is a fact that TRANSFAC contains only sites from eukaryotes, but
it is kept up-to-date at a faster pace than TFD.