gcc stands for "GNU C Compiler" (am I right).
It is the program that turns it from it's C source code (the readable format, AKA the programing language) into a executable file (Under WIN32, a .EXE or .COM file).
Usualy, the latest versions of eggdrop, that have been compiled to run under the WIN32 environment, are available from
http://sourceforge.net/projects/windrop/
At the moment, the most current available from there, is 1.6.8 (which is beta quality). 1.6.7 being your request is available.
On the site, that have listed a version CVS, which sugests it is version 1.6.8. This version, while being stable, is not recomended, as it is the most current code available, and can have bugs in, that will be fixed by the real 1.6.8 version.