vector origPos = (vector)llList2String(blah,0);
rotation origRot = (rotation)llList2String(blah,1);
vector posBase = (origPos-llGetPos()) / llGetRot();
posBase.x = posBase.x*-1;
vector revPos = posBase*llGetRot();
llRezObject("mirrorObj", (llGetPos()+revPos),ZERO_VECTOR,origRot,-56);