The command is Set preference and it takes a string as an argument that specifies the preferences file section, the preference and its value.
Example:
Set preference, "User Prefs|Client Refresh=1"So, I would guess that it would be something like:
Set preference, "Columns|Mail View=0, 25600, 1, 1, 33954, 1, 2, 121203, 1, 3, 230400, 1, 4, 21490, 1, 5, 25600, 1, 6, 28151, 1, 7, 38400, 1"for example.
But, that didn't seem to work (even after a restart) when tied to ctrl / in keyboard shortcuts under Application or Mail Window. You can mess around with it to see if you can get it to work though.