How to change maps in legacy (internal maps)

I'm playing evilution and wonder how to use warp in legacy.
Guess I have to use the map command but I don't know the right parameters.
Tried map 20 and e?m?, the name of the maps but with no result. Can someone help here?

Did you try idclevXX (where XX is level number, like 20 for map20)?

Thanks for your answer, Tarin.
I did try that, unknown command. The error message after using map xx is something like cannot find internal map, add .wad for external map. Legacy names maps from evilution and plutiona after doom 2. But commands like map the factory ( with or without _) don't work, even when using the doom2.wad.

I'm not using Legacy, so I'm more or less guessing here. Did you try "map mapXX" (instead of "map XX")? idclev is not a console command, just enter it when the game is running (not in the console, but when you can control the player).

Thank you very much both work!