Hi,
I believe that your projects are having an integration with IM module and so you must be having some appropriation requests in IMA11. Isnt That..? and the field you are looking is IZWEK which is available in table IMAKPI
I actually dont think that there is any report from where in you can populate this field. But you can try following options.
1. Execute CN41N and click on dynamic selection icon (Third from the left). Drill down Master data WBS element. Search for Investment Reason. Double click on it and that field will populate on the right side.
2. Search your entry(F4) in Investment Reason field and give the project number and execute.
OR
1. Execute SAP1 and go to Investment Management from SAP menu and search for your report where investment reason field is populating.
OR
1. Execute IMR4 transaction code. On the home screen, you will find the field as Reason for Investment.
OR
1. In case, if all above doesn't work then go for the development. Ask ABAPer to develop a report for you because you will be knowing your table name, field name.
Regards,
Amit Rajoria