NOTE: This command is changed a bit on newer trunk versions,
scroll down a bit for the new version!

On older trunk versions and stable:

command is the name of the current character (strcharinfo(0))
followed by ':' and the command and it's parameters.

Example(s):

//Will be executed as if a lvl 99 GM done the #option command.
charCommand strcharinfo(0)+":#option 0 0 0 Roy";

Newer Trunk version:

The big change is that the character name is no longer needed.
This also enabled the commands to run without a player attached (according to Lance).

Example(s):

//this would do the same as above, but now doesn't need a player attached by default.
charCommand "#option 0 0 0 Roy";