Mapping fields on TR

Hi Friends

I am extracting 3 fields (partnr, roletyp and sobjekt) from vdgpo.Now i want to map the fields partnr and sobjekt based on roletyp.

If roletyp = TR0120 then

zauthdrawer = vdgpo_partnr.

If roletyp = TR0992 then

zstateclk = vdgpo_partnr.

If roletyp = TR0998 then

zcredctrlr = partnr.

If roletyp = TR0999 then

zadminmgr = partnr.

If roletyp = TR0995 then

zcredmgr = partnr.

If roletyp = TR0996 then

zadminasst = partnr.

If roletyp = TR0997 then

zmktasst = partnr.

Your reply would be richly appreciated.

Regards,

Chama.