For the particular GL account, using the t-code FS00 goto the tab "Create/Bank/interest". There you should see the field status group for that GL account.
Goto t-code OBC4. Select your Field Status Variant. Then select the Field Status Group which you found for your GL account. Click on this Field Status Group and go to "Additional Account Assignments". There you should be able to set the status for each of CO-PA attributes.
Let me know if this worked for you and pls assign points.