It's a signal pin, so it will not take much current. The signals are driven with 5V from the Chameleon side (as opposed to some modern VGA products only driving 3.3V), so that would work with an appropriate resistor divider
The effort still sounds high for special (=unusual) monitors to work. Like I wrote in a different thread, we have a bunch of 50Hz-compatible 19" Eizo monitors (1280x1024 flat panel) that will go on sale in our shop soon. Price will be "50 EUR for 50Hz", and I'll put that online as soon as all cables have arrived (still waiting for an audio cable to come in). Might take a few days until I have added "bulky shipment" to the shop system.