In the Accordance Help, I read the following about asterisks:
An asterisk indicates a global wild-card; that is, any number of letters in a word. Standing alone or as part of a phrase, the asterisk signifies any word. (When searching for Verses the asterisk stands for all verses.) For example, the argument "sing*" finds any word that starts with "sing" including "sing", "singer", "singleness", etc., and "b*g" finds any word that begins with b and ends with g, regardless of its length.
Based on the last clause in that paragraph, I would infer this search would work as expected:
"*(ךםןףץ)?*=" <AND> [RANGE 1QIsaa]
The search queries for those occasions where the final form is used in a medial position. But the results are not logically returned based on the instructions of the asterisks (e.g., it returns חזון). I would expect, as in the example above, the second asterisks following the parenthetical subgroup to require Accordance to find only those occasions where the final form is in the medial position, but have additional Hebrew characters following.
I can get the results I need with this (let [all medial forms] = אבגדהוזחטיכלמנסעפצקרשׁשׂת):
"*([all medial forms])?(ךםןףץ)?*=" <AND> [RANGE 1QIsaa]
I would have expected the additional ?[all medial forms] to have been included within the final *. This seems like a bug (of at least some sort) to me.