BAPI create internal order with assignment for fields for "Assignment of investment program"

Hello, everyone,

I have the problem that I'm looking for a BAPI with the creation of internal orders that can also fill the fields relating to "Assignment to investment program".

M.E. can neither

BAPI_INTERNALORDER_CREATE yet

BAPI_INTERNALORDER_SAVEREPLICA

Do you have any tips for me?

Many greetings

Udo