If you mean "back at you" as a reply to a greeting:
* אַ צוריק (a tzurík) - This is the most common and literal translation, meaning "back."
* אַ צוריק־גרוס (a tzurík-groos) - This means "a return greeting," more formal but still acceptable.
If you mean "back at [place]":
* צוריק אין [place] (tsurík in [place]) - This means "back in [place]"
* צוריק צו [place] (tsurík tsu [place]) - This means "back to [place]"
If you mean "back at it" as in resuming an activity:
* צוריק אין די שפּיל (tsurík in di shpil) - This means "back in the game," referring to resuming an activity.
* צוריק צו די אַרבעט (tsurík tsu di arbeṭ) - This means "back to work," more formal but still acceptable.
If you mean "back at [time]":
* צוריק ביי [time] (tsurík bay [time]) - This means "back at [time]"
It's always best to consider the context and choose the translation that best fits the situation.