Though Slime's answer is very thorough, he missed another nice feature...
If you want to rotate a position, simply apply the rotation to a vector
using vrotate, like this:
#declare NewPosition = vrotate(OldPosition,RotationVector);
And voila! The position gets rotated! :-)
Regards,
Tim
--
"Tim Nikias v2.0"
Homepage: <http://www.nolights.de>