It should be directly in the folder you installed EQ into. Normally that would be something like
C:\Program Files\Sony\Everquest or something like that. Of course, the simplest solution is probably just to click Start > Search and search for files and folders and just put "eqhost.txt" in the search field and let Windows do the work for you. Another way is to right click your EQ icon on your desktop and it will show you the path to where EQ is installed at. Note that you will still need to find eqgame.exe as well and make a shortcut to that so you don't patch. Just follow this guide basically:
http://www.eqemulator.org/wiki/wikka...akka=PlayGuide