If you are carrying any items or if there are any items owned by you in the ship, or even if there are any NPCs or droids in the ship, then you should be able to pinpoint the exact location by looking at your item/NPC/Droid inventory.
If that doesn't work, then you're out of luck. The best idea for extraction would be to describe the ship, give its name, type of ship, and system where you are in, and number of passengers. Usually, there are no two of the exact same ship with the exact same name at the exact same location with the exact same amount of passengers.
Also, considering that you entered a system, you will be in at the edge of the system you exited at. You may want to mention that too to your potential savior.
____________Time to go to war with the Flame Tigers