Hi,
You have these possibilities:
- Create an enhacement implementation in FM RV_SALES_DOCUMENT_ADD. You should activate the "In update task" option if you want to debbug.
- Create a new output with medium 8 and assign a routine to add your code.
- Trigger a workflow in sales order creation (Tx SWEC).
- Likely there is a LIS routine that your system are using to save statistical information.
First and second options are the easiest.
I hope this helps you.