Well it doesn't seem to exist, this will do it in code:
...
muck1_entity = pl->FindEntity("box1");
csRef<iPcMesh> pcmesh = CEL_QUERY_PROPCLASS_ENT (muck1_entity, iPcMesh);
iMeshWrapper* mesh = pcmesh->GetMesh ();
csXRotMatrix3 x_muck2_rot (4.7f);
mesh->GetMovable ()->Transform(x_muck2_rot);
...