Student or Learner
I might have misspelled it, but I dare say that's what I heard instead of "god damn it." Does "dad gumm it" ring a bell?
Yes, "dadgumit" (different spellings abound) is a common euphemism (particularly in the American South) for the expletive you mentioned. Likewise, many older folks might say "What in the Sam Hill?" instead of "What the hell?" Lots of people were raised with the belief that profanity was bad, so many different euphemisms for otherwise vulgar expressions evolved.