The reverse is easier to find! If you know your Civil Registry Number (called Rakm-el-Sigill) in Arabic, it is easy to trace it to a geographic area. If I remember correctly, this number originated in the census of 1936. It is usually noted in all ID cards, passports, voting cards, etc. Think of it like a Zip code! I am not sure how far back in time, the Government started the practice of using this number. If your ancestors left after 1936, I am sure that they would have such a number on their travel documents.
The problem is if you don't know this number, it is difficult to find it, unless you know the name of your original village or town, and the religious denomination of your ancestors (Maronite, Greek Catholic, Orthodox, Sunni, Chiite, Druze, etc.)
If you happen to know the name of the town, the mayor (called MUKHTAR in Arabic) can find you this number.