Actually this is exactly the opposite of how Navision works. I am not sure what systme you are coming form, but really its much easier if you look at Navision in Navision terms, rather than thinking “this is how our old system used to do it, how can I duplicate this in Navision”.
Basically in Navision you have your main ledger, the General Ledger. and then a number of sub ledgers, that store extended detail and have extra functionality. If you just need to make basic financial entries, then you post in the General Journals and it ends there. BUT if you need extra functionality or more detail, then you post in a Sub Ledger, and then that journal poss entries in the General Journals that are then posted into the General Ledger.
So in your case, you wouldn’t spend (aka waste) many hours and dollars of development time, instead you would do it the Navision way, and post a Job’s Journal that would then create the appropriate General Ledger posting.