[Wien] How to force a particular charge state

[dil...@jncasr.ac.in]

Hello users,

In Wien2k I want to study Co doped ZnO and I want to force the Co atom to be in 
the Co3+ charged state instead of Co2+ and run the scf. How will I do that?

-Thanks
 Dileep Krishnan
 c/O Dr. Ranjan Datta,
 ICMS, JNCASR,
 Jakkur, Bangalore.