Open and go back with arrow key

I would like to use left and right arrow key to navigate into folders in detail mode like in folder tree.
So I have add left key as alternate key for backward (command go up back).
What would be the command acting like enter key : open selected folder ? I have tried go up forward without success.
Thanks !

Go FROMSEL is the command you want.

Excellent. Thanks.
I have found it in the help. Next time I will take some time to search better.