Pelvis Rotation MaxScript

Hi,

I am new in max script. There is something that I could not understand about rotating the pelvis. For example:
Q2 = quatToEuler (biped.getTransform $'Bip01 R Foot' #rotation)
(eulerAngles 180 90 0)

QP = quatToEuler (biped.getTransform $'Bip01 Pelvis' #rotation)
(eulerAngles 173.182 -89.9999 0)

biped.setTransform $'Bip01 Pelvis' #rotation (eulerToQuat Q2) false

When I set Q2 as above

the final rotation is

quatToEuler (biped.getTransform $'Bip01 Pelvis' #rotation)
(eulerAngles -180 89.9999 0)

but it should be (eulerAngles 180 90 0) since Q2 is equal to this value.

Is there something that I am missing to change before setting the pelvis rotation?

Thanks a lot.

It's quite difficult to understand what you have here.
Q2 - is the rotation of the Right Foot right?
QP- is the rotation of the Biped pelvis?

So what is your relationship between the right foot rotation and the pelvis rotation?