Hi, Probably A Very Simple Question from a Newbie

Hi everyone.  Using an application that was created wit FileMaker pro. (process master).  I'm interesting in importing excel or csv data.  Since it's a wrapper ABOVE filemaer I'm using I'm not entire sure of what the underlying DB is tho I would think it's 1 main table with lots of records.

I should say at first, there is an option to export records from this SW into  Excel amongst other things and the resulting xls file Does have column names

There is an option to Import under File menu, which seems to enable loading files of any format.  

Is it likely as simple as importing a file with the same exaxct format/column names as the one the SW Export will create new jobs?  It seems like the Main Primary key is something called "Job ID", is there a threat of me over writing an existing job when importing

unless I change the job id field to one not used?  or does FM figure that out on it's own?

If the mapping upon import DOEN'T work like my assumption - I thought what I'd do is just enter lots of text values in the csv/excel and see which ones get mapped where?