Solved Diffs/ Rotators interaction with steering (lua?)

Hi,
I successfully implemented rotators to my walking machine (wohoo), but now I'm stuck with a steering problem. I planned a steering in the same way a tank steers- one tank track, or the legs on one side of my walking machine, get stopped or turn in the opposite direction to steer.
Would it be possible to somehow change wheelDir according to some sort of input? Maybe the lua wizards could help me with that.

Code:

 "rotators":
    [
        ["name","[group]:","node1:","node2:","nodeS","nodeArm:","wheelDir"],
        {"radius":20.200},
        {"brakeTorque":110000},
        {"parkingTorque":330000},
        {"propulsed":1},
        {"speedo" : false},
        ["spin_motor", ["spin_motor"], "nl8", "nl47", 9999, "n29", -1],
        ["spin_motor1", ["spin_motor1"], "nr11", "nr52", 9999, "n29", -1],
        ["spin_motor2", ["spin_motor2"], "nl154", "nl113", 9999, "n155", 1],
        ["spin_motor3", ["spin_motor3"], "nr157", "nr137", 9999, "n155", 1],
    ],

There is no visible mesh in the file, but I'm sure you know how to make the n/b visible .

Edit: I would also be happy with something like two engines, controlled by the left and right arrow key, one engine takes one side. But that's probaby even more complicated than other solutions.

 

Alright, I found a workaround, just some thrusters that apply thrust in the opposite direction of the rotators on one legside, with corrected open diffs.
Not the prettiest solution, but it works .