You can do it two ways: 1) make the script a unix shell script and run
it
under Interix (the Unix component of SFU) with cron/at, or 2) call the
utility directly from the CMD.EXE script.
I think (1) is more straight-forward and clear personally. A shell
script is a better
programming environment than CMD.EXE.
If (2) then you are likely not wanting a console window to open.
Use the utility "psxrun.exe" to invoke the Unix/Interix utility from
Win32/CMD.EXE.
There's a manual page (man psxrun) with more details. An example is:
psxrun -u -- /usr/local/bin/gzip file
All of the arguments and options to the utility should be in Unix
syntax.