How to exclude a linked prim from rotating?

Is there a way to exclude a linked child prim from rotating? The root prim has the script in it using

llSetPrimitiveParams([PRIM_ROTATION, <0, 0, 0, 1>]);

etc....

Howeer, I have a set the I do not want to move at all. Is there a function to use to tell them to be still?

Thanks,
Thorne

Rephrase...can I lock a child prim in pace so it does not rotate with the parent prim?

whenever the parent prim changes rotation,
set the child prims rotation to the inverse of llGetRootRotation()

// FUNCTION
rotation Inverse(rotation r) { r.s = -r.s; return r; }

// IN CODE ("base_rot" = the rotation that you wnt the prim to end up
// pointing but is not needed if you want it to end up pointing 0,0,0...)
llSetLocalRot(base_rot * Inverse(llGetRootRotation()));

No, cannot seem to get that script to work. I get a syntax error on

rotation Inverse(rotation r) { r.s = -r.s; return r; }