It was a while ago but I believe I've used touch on windows, from cygwin. You just need cygwin1.dll in the same folder as touch.exe, and call it from bash.exe.
There are ports which do not require the cygwin emulation layer nor a *nix shell to launched from:
C:\temp>touch foo2.txt
C:\temp>dir foo2.txt
Il volume nell'unità C non ha etichetta.
Numero di serie del volume: 0464-729A
Directory di C:\temp
07/06/2007 21.50 0 foo2.txt
1 File 0 byte
0 Directory 3.396.943.872 byte disponibili
OTOH, does anybody remember Borland's touch.com?