What type of codec is it? ProresHD, DVCPROHD? These codecs will not work anywhere outside of a FCP system. Even a Apple computer without FCP will not be able to work with them. Prores is a nice codec but you have to have FCP to use it. There is no way ever a PC system will ever be able to use those codecs. A lot of Apple people make this mistake all the time because they think Apple is everywhere so they forget that they may be using a codec other people will not be able to use.
If you can have them use photojpeg or some other universal quicktime codec.
Avid does have a free DVCPROHD quicktime codec but I'm not sure if it will work with Apple DVCPROHD files or not. It is a very slow codec so I have only used it once for an animation project I was on with another team.