Codes in Dolphin?

[Tasty Pumpkin Clock]

Does anybody know how to use codes in Dolphin? I use Dolphin because it's easier then putting stuff on the Wii. I can't use the "Flaming Blue CSS" menu or switch a level to Online Training, etc etc. Anybody know how?

[Tasty Pumpkin Clock]

I'm also wondering if I get could get a link explaining how to use codes normally.