Achievement Custom Game against AI?

OK, came back to play SC2 for a month now, and i was looking on achievement. They say i need to play some custom games agaisnt AI on very easy, easy, normal, etc. Thing is: when i go to the custom tab, i only see a lot of maps, edited from other player, and after there is a “mixed” tab and a arcade tab… nothing about Custom Games > Medium A.I. / Custom Games > Harder A.I. / Custom Games > Elite A.I… Where the Hell are these custom things?

And… if i want to play on multiplayer against AI, i can’t play 100 match has a terran on easy, because its auto set the dificulty…

Sorry, i am kinda go crazy going in all options tabs ingame and can’t find what i seek…

“Mixed tab”? Dont you mean melee? What you want to do, is go to custom games > select melee from the top bar > select the map you want to play on > click add A.I. in the top right, and the AI will be added to your lobby. You can change its difficulty level, race, strategy or strength of its units (handicap). In order for the game to count to the achievement the handicap of the bot must be set to 100% and it has to be a 1v1 game, you cant play you + 6 bots vs 1 bot. You can freely change its race and strategy.
Also the games won with AI from the multiplayer tab, and games won with the custom AI count to diffrent achievements, so if you are crazy enough to play hundreds of boring games vs ai just to get all achievements, you have to do that from both multiplayer tab and in custom games.