Why you don't just use normal cheats?
Rightclick your game -> properties -> set launch options -> -console
Ingame type sv_cheats 1 in console and use god for godmode and impulse 101 for weapons.
In Half Life you don't need more and the game make more fun without cheats
That would disable the achievement, if you just enable the godmode, the game will automatic disable the achievement. And it would be very nice if CH make the Trainer for the orange box, and do the auto update just like L4D and L4D2.
Are these trainers closed or you will update it anyway? I know, pretty old game...
You will need to put a request in for a trainer. As that one appears to be a user made one. Who is no longer here.
So go to www.cheathappens.com/requests.asp