If you want to recreate your ME1 character from scratch in ME2 by converting slider values into a ME2 face code, here's how to do it. It's very simple, but you need to know what the slider values were for your ME1 character.
Note 1: ME2 skips the letter 'O' when generating the face code, in other words when you bring the slider (e.g. neck thickness) to position 24, the game encodes it with the letter 'P' in the face code, instead of 'O' (e.g. M(22)->N(23)->P(24) ). The letter 'O' isn'