having software issues with throttle quadrant build.

hey guys, hope someone can shed some light on my project. basically what i am doing is using the pots, and controller board from a gravis extreme joystick. the issue i am having is software related and i know it is as when i go into FSX and set the x and y axis for prop/mixture(throttle have no issues with) ill go to fly and of course the prop/mixture only moves about 20% one way and 20% the other so im not getting the full range as the software is basically telling the pots that the middle is zero and goes from negative to positive range which is normal for an x/y axis as joysticks are centered. what i need to do is have the pots start at zero and go up in range instead of the middle being zero and going from negative to positive. i know there is something i am missing and i have no clue how to set fsuipc for this(i have paid version). just trying to get the software issues worked out before i go and build the TQ. ive seen some users who just used joystick parts/boards and fsuipc to set it up, and i cant find any contact info for the people who have done this....hope this makes sense if i need to clear anything up just let me know. this is driving me nuts i tell you!