Hi Ahamefule
I suggest create a custom report . Which picks up all data from table SWWWIHEAD and other workflow tables like : SWW_WI2OBJ etc ..
This report will be run once daily to store the data in a custom table .
If however you want a real time update of the data i.e evey time a customer approves it it gets stored in a table then you can use BADI DOC_SAVE on event approve and that should also serve your purpose
Capture SYUNAME for approver ID and SC number .. etc . I am not sure why you want to capture the work item number that is a technical data not of any use for business ...so you might want to check on the requirement
As a last resort I would suggest you update the logic in the workflow events which are getting triggered during agent determination ie. BADI /SAPSRM/BD_WF_RESP_RESOLVER or /SAPSRM/BD_WF_PROCESS_CONFIG and see which one is suitable to place your cart ..
That should be able to help you progress
Let me know if this helps
Regards
Vinita