Hammer can only compile a map FOR YOUR MOD or ANOTHER HL MOD only. The following applies for compiling a hl mod/minimod map. Copy the half-life compile process (in advanced mode) and at the last command ($game_exe +map $file -dev -console) change it to ($game_exe +map $file -game
mod name -dev -console) without the *, rename the compile process to the mod then you're done! Remember to set up the mod first in the options!
Also if you want to tweak hl for your mod, you'll either HAVE to:
-code it
-model
-script
To create a mini-mod, go here:
http://twhl.co.za/tutorial.php?id=60