Short answer:
Yes.
Explanation:
Here is the text of Regiment of Black Crows for reference:
The question about Regiment of Black Crows canceling an Ahunt attack has been addressed in a couple digests:Playable at a tapped or untapped non-Under-deeps Ruins & Lairs. May not be attacked. Discard this ally if its controlling character is wounded. Tap this ally to cancel a hazard creature attack not keyed to a site and to put the creature's card back into its player's hand. Cannot be duplicated in a given company.
andICE RULES DIGEST #111
22-07-1998 Author: Craig Ichabod O’Brien
QUERY 9
[…]
6. What effect does tapping Regiment of Black Crows have on an “Ahunt” Dragon attack? Is the “Ahunt” long-event sent back to hand?
Yes.
While it is true that Regiment of Black Crows' text states “put the creature’s card back into its player’s hand” and Ahunt cards are not technically “creature cards”, it is important to note that RoBC’s text doesn’t actually say to return a “creature card” to its players' hand, but rather the “creature’s card”, i.e. the card with the creature attack. This committee therefore concurs with both of the quoted NetReps in determining that the card from which the attack initiates is sent back to its players hand so long as the attack itself is a creature attack, which would be the case for Ahunt dragon attacks (per their text).CoE RULINGS DIGEST #122
23-03-2011 Author: Mikko Vihtemäki
QUERY 5
[…]
2. What about “Ahunt” Dragons, then? Are they returned to owner’s hand when Regiment of Black Crows is used to cancel the attack?
Yes.
It is important to note here that this answer doesn’t contradict the previous answers by both Ichabod and Mikko Vihtemäki, but both of them only answered with a simple “yes” but gave no further explanation. That’s the reason why this committe decided to publish an extended answer.
In the case of creatures that attack from an off-to-the-side state, like Bring Our Curses Home or Foes Shall Fall, after reading the comments in the original draft published, we had an interesting discussion and found out that it is a more complicated issue than we had anticipated. For now, and until we come up with a different solution, the official answer to that question remains the latest by the CoE (that is, CoE #55 Q2).