Making a game trainer in C++?

Ok so i've messed with games before, but now i would like to make a trainer only problem is that there memory adresses changes every time i play it on a different computer or restart the game. Now i need to find a pointer but have no idea how.

So how do i find the pointer to the adress for ammo for any weapon with a memory scanner like CheatEngine 5.4?

From stackoverflow

• http://forum.cheatengine.org/viewtopic.php?t=26540 i found this on the cheat engine webpage they have a section dedicated to pointer it could prob help.

• • step 1. search through memory for the value you are looking to change, and store all match locations
  • step 2. do something in the game to change the value to a new value
  • step 3. check all of the match locations, one of them should have the new value in it.
  • step 4. write whatever you want into that location.