Yes you can submit and then resubmit that same game, no matter the circumstances of your original victory, or defeat.

You can only do it once and it simply overwrites the previous submition with no input from the player whatsoever.

Don't try and do this across different builds though. I tried it way back in early DA days or even late in DL and submitted a game under one build and then resubmitted on a later build and got cheat flagged. I know of no other reason why i got the flag so i have always assumed it was the resubmittion and i have just made sure not to use another build to resubmit a game.