The Rabbit Approach: After matching up identical characters, here is a sequence of (cipher text character position) minus (clear text character position) wrapping from beginning to end as necessary. This sequence represents taking the clear text character "I" at position 117 and shifting it backwards by 32 characters to position 85. The "space" character at position 85 is then shifted backwards by 31 characters and so on. Restarting the sequence three times is done to avoid occupied positions.

Start at clear text character 117 then shift by: -32,-31,-23,-24,-26,-26,-37,-33,-31,-40,-25,-31,-35,-24,-26,-19,-37,-33,-23,-38,-35,-16,-32,-38,-22,-41,-37,-20,-30,-17,-26,-25,-32,-22,-25,-24,-26,-29,-34,-30,-20,-35,-32,-31,-26,-24,-24,-40,-24,-22,-19,-21,-26,-32,-24,-26,-40,-23,-28,-41,-16,-35,-18,-32,-27,-15,-8,-31,-16,-18,-31,-23,-31,-37,-18,-32,-23,-38,-35,-15,-31,-38,-29, Start at character 115: -35,-22,-26,-31,-12,-33,-23,-20,-30,-38,-30,-33,-23,-38,-38,-30, Start at character 111: -29,-16,-36,-31,-25,-16,-38,-24,-41,-28,-26,-21,-33,-30,-23,-36,-18, Start at character 108: -15,-29,-35

The Turtle Approach: This sequence is also the (cipher text character position) minus the (clear text character position) but it is ordered from clear text position 1 to 123. This sequence represents taking the clear text character "Y" at position 1 and shifting it backwards by 12 characters to position 112. Then the "O" character at position 2 is shifted backwards by 23 characters and so on.

Going from clear text character 1 to 123, shift by:  -12,-23,-16,-35,-38,-38,-26,-31,-21,-34,-15,-40,-22,-32,-35,-32,-22,-21,-41,-30,-27,-30,-37,-24,-27,-33,-18,-23,-44,-31,-24,-31,-31,-18,-31,-30,-19,-26,-29,-20,-33,-19,-24,-41,-32,-35,-21,-24,-35,-29,-18,-30,-38,-23,-38,-20,-32,-26,-22,-25,-33,-24,-36,-35,-26,-36,-16,-26,-20,-25,-37,-28,-26,-26,-18,-23,-37,-37,-23,-22,-38,-16,-24,-38,-31,-23,-32,-38,-24,-38,-30,-24,-29,-32,-23,-26,-16,-31,-30,-40,-28,-31,-16,-26,-31,-8,-23,-15,-33,-35,-29,-33,-17,-25,-35,-30,-32,-41,-31,-26,-15,-25,-40

For both approaches, a number of similar sequences are possible, particularly with the abundance of E's, T's, and spaces. But I have been unable to find a sequence that can be described by a simple algorithm.

Assuming there is no simple algorithm, this cipher sequence would be created by generating numbers with some degree of randomness and avoiding previously occupied locations. The recipient of the cipher text would also require the cipher sequence for decoding.

2nd attempt - Trying to find a sequence using only the position of the characters has yielded no meaningful result. It appears that a value for each character is also being used. I think the cipher uses the position of each character in the clear text (from 1 to 123) minus its character value to determine its position in the cipher text. If the calculated position is less than 1, it is wrapped from the beginning to the end.

The following character values are the best that I have found so far. This is not the final answer but the results are closer than any of my previous efforts

Character   ?   ,   .   +   A   B   C   D   E   F   G   H   I   M   N   O   P   R   S   T   U   X   Y
Value       42  41  40  40  40  35  37  38  35  35  31  31  30  24  25  24  25  23  21  18  17  18  13

When the cipher text position is calculated from the clear text position minus the character value, the results are as follows (using "+" to help track the spaces):

My cipher text  H   A   ,   +   E   I   T   G   +   X   T   B   +   T   D   S   T   +   R   E   I   +   A   T   +   E   +   O   T   U   A   N   T   +   C   O   S   M   D   N   A   T   E   O   +   D   N   +   N   U   C   E   Y   +   H   R   N   U   E   S   .   +   I   H   A   E   T   +   C   P   T   +   R   F   +   +   N   E   ?   G   I   T   O   Y   +   I   A   +   C   R   U   Y   A   +   O   U   D   E   T   +   O   T   U   C   N   H   I   R   U   ?   E   Y   +   I   E   H   A   +   P   S   T   +   R
OP cipher text  H   A   ,   +   T   I   T   E   X   G   B   +   +   +   D   T   E   S   T   R   I   +   A   T   +   U   E   +   A   +   O   N   T   C   T   S   O   M   N   D   E   O   T   A   +   D   N   +   U   E   Y   C   N   +   H   R   U   S   N   .   I   E   T   H   +   A   E   P   T   +   C   R   +   +   F   +   T   N   G   E   Y   I   ?   O   I   +   A   +   R   C   A   +   U   O   D   U   T   Y   E   +   C   O   H   N   T   U   I   ?   E   U   R   Y   I   +   H   E   P   S   A   +   T   +   R

How three spaces come together in the OP's cipher text, is one peculiarity that I do not understand. I'll keep working on this but would be happy if somebody else found the correct solution.