Not the way to solve the OP's problem, but for those who come across this in the future:

• gnu grep
• egrep
• tcgrep

I also have what I hope is a comprehensive list of *nix-like utilities for Windows here.

Update: It would seem, however, that several of those links are b0rk, so this should be the updated version:

• Perl Power Tools
• Cygwin
• The Berkeley Utilities - 40 unix commands ported to DOS
• GNU utilities for Win32
• Unix Utils for DOS
• CMD Line Tools for Windows 95/98/NT/2000/XP
• Batch File Utilities

HTH,