Good Morning, Gurus.
EARLIER i have created custom field of date type (default sy-datum ) using customer_exit in ML81N as shown below.

To achieve the above functionality, I have added new field to table ESSR so that the value gets stored in the table ESSR.

I have got new requirement in MIRO transaction. Under Invoice, payment tab , we have baseline date, payment terms , due on
fields.
I have to set validation in such a way that baseline date in MIRO, should be mapped with the custom invoice receive date field ZINVREDAT created on ML81N, and based on
pyt tems in MIRO the Due on date has to be default value.
To make it more clear,
whenever, user gets into the payments tab, the baseline value should be from the table ESSR-ZINVREDAT
and when the user selects pyt terms , the due date should appear by default.
if I select P042 in Pyt terms, the due on should be set to Baseline date , (ESSR-ZINVREDAT) + 7 days,
P043 = Baseline date (ESSR-ZINVREDAT) + 15 DAYS
P044 = Baseline date (ESSR-ZINVREDAT) + 30 DAYS.
The due on value should be by default while posting MIRO (faded) as it is already as shown below. .

How can I achieve this ?