Diifferent Accounts based on Valuation Class /Material group Shorttext -PO

Hello Sapient

We need to differentiate the Posting for short text PO . we want the Asset / Office supplies / Services to post in to a separate G/L Account .We seperate it by Material group , but the posting cannot be done by valuation class assigned to the material group . How can we handle the WRX using valuation class or by any method. what i am referring is all for PO without material master. .

Thanks

Jeevan