Connect external potmeters to rapid- and feedrate override sliders in QTDragon

Dear forum members,

I am progressing well with the conversion of my 1980 MAHO MH300 to a linuxCNC based machine. I made a replacement console consisting of a high res screen (not a touch-screen) and keyboard + Estop etc. console (see attached image). I copied the layout of the console, including two potentiometers from a DMG machine. On the DMG these are intended for rapid traversal override and feed override. I am now trying to make QTDragon_HD to run and read that this GUI was not intended for keyboard use.... However, I do like the way the QTDragon gui screen is build up and would like to try to adapt it in such a manner that I can set these overrides with the potentiometers. Similar to the Estop I would like to go for an implementation where the console hardware (physical estop button and physical potentiometers) set the hal signals and that the QTDragon_HD GUI only displays (follows) the setting set by the button and potentiometers. For the Estop I think I made this work, but from what I have read thus far I think the QTDragon_HD does not allow these override sliders to be set by another HAL output. Is this indeed the case? I am still quite inexperienced in LinuxCNC, HAL and Qtvcp, maybe I overlooked something. Any help or suggestion is welcome! 

Dear forum,

I found more information related to what I am trying to do on section 2.8 of  www.linuxcnc.org/docs/html/gui/qtvcp.html#cha:qtvcp  . I will first try to go through these sections and see how far I can come...

@ the forum moderator: feel free to remove my question above.