Hi Rev
1. Am not sure if Amount field can be added in SORT fields in DMEE. I assume what you said is correct
2. You can use Event 00 and Function Module FI_PAYMEDIUM_DMEE_00 to fill the Sort Fields you want and then it can be used for Sorting
3. Also, see if Event 30 and Function Module _30 can be used to Order the fields
Ajay M