.hqx and .sit files

[apolodor]

hey, i have a problem with .hqx and .sit files. i'm running win xp sp2 and i have installed Stuffit expander. the files were downloaded from the internet. as i expanded the *.hqx files, what appears is a non-executable *.file file, sized 0 kb... i also have a *.sit file, which can be viewed with stuffit. i extracted the archive's content to the desktop and the files are of type *.file sized 6Mb and a *.rsrc file. neither can be opened.
do i heed another program to open and run them (there must be an executable inside them, because the *.sit should contain a program and the *.hqx some games and game updates) or they are only accesible on mac computers?