Exporting and re-importing to a custom module

Exporting and re-importing to a custom module

I'm faced with limitation of fields and features from the task module so i decided to make a custom module. but i am having issues with re- importing back the data in the custom module. how do i accomplish this by keeping the original related contact to that imported record.


When i export all data from the task module related contact name is transformed as a unique ID like this..zcrm_292483000006045015.
but when i try try to import this back by using the same ID to the new related field contact look up field  it is not recognized and that field seems to ignored


What am i doing wrong?