OOOh i get it now. Your trying to make a patch with HCE Right? You cant do that. What youll want to do is use hce to edit the cache, save it, FTP into the Z,X or Y folder and grab the cache, then use ppf studio to make the patch there.
What ever you do youll need to know how to make ppfs anyway so click MEWARNING to be honest any mod that you make using only HCE will pretty much be considered crap by the moddding community since it will only projectile swapping, model swapping, or damage/physics change. If you want to make proper mods youll need alot more than HCE. id suggest starting with HMTv3.5, sparkedit, ppf studio. And the Ultra Block from halomods.com or the halo NMp site whos address i dont remember.