Triple head driver help

hello there.

i am currently running a TripleHead2Go, but i have come across a snag

you see, the TH2G is actually 100m away from the computer, so to get the signal there, it is running through a distribution amplifier, and then into RGBHV tails, and then it runs all the way there.

signal quality isnt a problem, as the cable is quite high quality, but the main problem is that since the computer isnt running straight into the TH2G, it isnt detecting that it is there, and thus, whenever the computer is restarted, it defaults to a standard resolution instead of the 3072x768 resolution i want to run.

when i try to set the resolution back to 3072x768, it is no longer in the resolution list, even though i have unchecked hide modes the monitor cannot support, and the only way to get back to that resolution is to totally unplug the TH2G and bring it to the computer, plug it straight in, set the resolution, and then take it back.

this process is getting very annoying and i was wondering if there was a way of modifying the default display driver to have 3072x768 in the list.