COPA OKB9 settings and characteristics group

Hi Gurus,

Client wants to post COPA documents (through FI entry) for certain cost elements. I maintained characteristics group and made settings as to which characteristics should be mandatory entry field at the time of posting to PSG as a real cost object. This group is assigned to the business transactions RFBU which is required for FI posting. I also maintained OKB9 settings and made PSG as mandatory for those cost elements for which PSG should be real cost object.

Now the requirement is, out of some cost elements in OKB9 for PSG , client requires entry for some characteristics as mandatory and only those characteristics should be displayed at the time of FI entry. But for some cost elements, the screen should be displayed with different characteristics

For e.g. for cost element travelling, PSG characteristics should be profit center and country but for cost element audit fees ,PSG characteristics should be sales org, division and cost center.

Now how can I assign two different characteristics groups for the same business transaction RFBU? Is there any way out?

regards,

makrand