2003 licence TSCAL server installation on windows2000 ?

HI

I have a Active directory with 3 domain , a parent one and 2 child domain.
Mycompany.local
Section. Mycompany.local
Siege. Mycompany.local
DCs on parent domain are in windows 2000.
Dc1. Mycompany.local is a lisence TSCAL server who manage more then 1000 TSCAL for windows 98 or XP (free licence until now).

My question is, :
Because i need to install new citrix servers on windows 2003 , i need to have TSCAL win2003 in my domain.
Can i install this licence on windows 2000 licence server on Dc1. Mycompany.local ?
Or do i need to upgrade Dc2. Mycompany.local to windows 2003 in the same 2000 domaine and add on it TSCAL service for adding theese licence TSCAL2003 without troubleshooting existing licence on 2000 ?