float angle = 90; //change to whatever angle you need.

integer prim_number = 1; // change to whatever prim number you need to rotate

float spinrate = 1.0; // change spin rate

float gain = 1.0 // change gain

default
{
state_entry()
{

Vector RootAxis = llRot2Euler( llGetRootRotation());

angle = angle * DEG_TO_RAD;

rotation rot = llAxisAngle2Rot(RootAxis, angle);

vector euler = llRot2Euler(rot) * RAD_TO_DEG;

llSetLinkPrimitiveParamsFast(prim_number,[euler,spinrate,gain]);
}
}