Glide wrapper is a magic thingie that makes glide available for people with non-Voodoo video boards (i.e. everyone nowadays). Glide is the API of the old Voodoo boards, and several early hardware 3D games support only glide, instead of OpenGL and Direct3D. WCP has a D3D mode which is in this case inferior to the Glide one. One of the problems of the D3D in WCP is the lack of some pieces of the crosshairs and the nav cross.
I can't remember where I found it, but a quick search to the tech support foruns and the internet will find it for you.