Hello and welcome!
Not likely a mac version coming (not for CoH 1 or 2), this is a small studio and there is no money in making mac versions.
That said, if the mac he is using is fairly new he should be able to install windows on the machine. Using bootcamp (which should be installed on his machine already) he can then choose to start his mac with either windows or the normal mac-os. This also requires him to make a partition of his hdd to NTFS since mac uses a diffrent filesystem. There are alot of good guides on how to do this though. When done, he can run any windows application as far as I know. Best of both worlds.
Good luck!
THX, ill make sure he reads this