Hi,
Try FBR2 transaction code. You can use FBR2 transaction code in LSMW . hope, it will help you to achieve your task. try in testing system. if you are satisfied than you proceed in production. otherwise you need to take ABAP team help
download the document numbers and use in the LSMW template.
hope, you will be getting errors in background. first try in foreground. share the LSMW file once you create, let me try some code changes. it may work or may not.