REG : Workitem Text for Global Workflow Administrator

Hi SRM Gurus,

I have a requirement wherein if the approver id is invalid the work item should go to the GLOBAL WORKFLOW ADMINISTRATOR.

I am achieving this in the RESP RESOVLER BADI, by checking the user is valid or not using the function module ' BBPU_CHECK_USER', in the in the method using the function module  'SWD_WF_DEFINITION_ADMIN_GET' and passing the same to the internal table ' rt_approver'.

Everything is working fine and I am able to get the GLOBAL ADMINISTRATOR, but the requirement is when the WORKITEM is sent to the ADMIN, a custom Work item text should be sent to the WF Admin as 'Work item text is ‘Shopping Cart number xxxx Technical Completion Approver determination failed.'.

Where should I give this text, I mean do I need to create an event along with an expression, and a new process level for the same.
If yes, where should I code for the approver check, as this should trigger only when the user is invalid.

Please help.

Regards,

Aakash Awasthi.