Alright, this could get messy. I can definitely give you some instructions for how to fix this (and other issues you might run into) but I'm going to have to add the disclaimer that while the following instructions did work for me personally, I don't recommend people try these unless they absolutely can't get things working the official way, and I take no responsibility for any issues that might arise. Presumably other people managed to get in using the regular version of wine and IR, so it could be down to a specific quirk shared by a small number of Macs.
Now that that's out of the way... I ran into that issue when I was first getting PC working but I was hoping it was specific to my setup. The way to fix it is to find a copy of glu32.dll (ideally from a Windows system, it should be about 128kb in size) and put it in /Applications/coh. Once that's done try logging in and you should find that the client comes up, but you may receive a directx error. You may also receive a directinput error.
The way I fixed this was to open up winecfg (run
winecfg in a terminal), go to the Libraries tab, find dinput in the library list, click edit, select 'Builtin, then Native', click ok and finally click apply. After that try logging in and see what you get.
Your winecfg should look something like this:
