Dear Julio,
I assume i understand your requirement. You want loan to be used for investment ?
Please correct me if i'm wrong? In case yes then in SAP TRM we have a concept of facilities which you can use.
Example i have borrowed 10 M from bank used the same to invest in FD. in this case i will create a loan with same amount and link the same into my product.
Again, Let me know whether my perception about your requirement is correct?
All the best !
Regards,
Jain