I don't think BT address which is in the form of MAC address (if you know what it means) has any relationship with
imei number, i.e. it can't be calculated from
imei number. BT address is suppose to be an unique number, i.e. no two BT device will have same address. That is to prevent conflict when pairing with other device. In your case, you can actually use any address as long as it is not same as the address of your other BT device and it should work. However, to program the BT address back to the phone, you need a tool to do that as it is not suppose to be set by the user using the phone alone. Hope this helps!