Refresh Rate

We have a little problem with Photon.
How can we set the optimal refresh rate for the monitor under Photon (QNX4)
if we have a Matrox Millenium II card? The crttrap detects it and installs
the driver and the modeswitcher, but the latter does not support the -r
option so the refresh rate is only 60 Hz.

Thanks
for the Help