Hammill, who starred in Saturday's 5-1 demolition of Bournemouth, rammed home from close range eight minutes from time to seal a 3-2 win at the John Smith's Stadium.
The former Wolves star has had personal problems but now seems to be settling into a wing-back role in a new-look Huddersfield side.
Robins cautioned him and said: "The more he reads about himself, and there's some nice things being written about him, you just hope he doesn't get carried away.
"It's nice when people write good things about you but they're doing it because you're working hard and preparing in the right way."
Robins was relieved with the win after Town twice came from behind to reach the League Cup third round for the first time since 2003.
He said: "I'm just glad we got the three goals and that also some other players are now scoring for us.
"Our passing was not good enough to maintain our shape and I had to change the formation twice as a result.
"We've got to be better. We weren't as good as we were on Saturday. The players have got to maintain the standards they've set for themselves."
Charlton boss Chris Powell called on his side to be more clinical but took plenty of positives from the defeat.
He said: "It was a real heart-warming performance and all that it lacked was the goals. We need to be more clinical and take chances when they come.
"We could have been two or three up by half-time and at 2-1 we were pegged back by a deflected goal.
"It was a good cup tie that ebbed and flowed but the performance gives me a lot of pleasure and there is a lot to look forward to."
The Addicks have only won once so far this season - against Oxford in the Capital One Cup - and Powell added: "We're going through a tough period.
"We just need something to pick us up. We couldn't see the game out but there are plenty of positives to take us forward."