This is a rather late response to this thread, but I just started looking into multi-boxing Neverwinter...
The following is copied from
http://co-forum.perfectworld.com/showthread.php?t=81117, an old Champions Online post about key bind commands, which should be similar to NW's.
The Alias Command
The alias command is for creating your own commands/functions. The command to create one is:
/alias <command name> "<command1>[<param1><param2>...][$$<command2>[<param1><param2>]...]"
Example
/alias helloWorld "yell Hello World!"
Then, type /helloWorld
Result: Your character will yell to the zone, "Hello World!"
Using {}
(Thanks to: Amasilver for helping with this section.)
When creating an alias, you may use {} which has a special function. This is treated as a marker of where to insert a string that will be passed to your alias.
Example
/alias helloWorld "yell {}"
(Now our alias helloWorld takes 1 string argument.)
Then, type /helloWorld Hello Everybody!
Result: Your character will yell to the zone, "Hello Everybody!"
Now, if you include multiple {} in your alias, EACH one will be replaced by the string you pass to your alias. Also, the string replacement gets interpretted BEFORE your alias is run, which opens up possibilities for more complex usage. Now for a slightly more complex example.
Example
/alias move "+{} $$ playersay Going {}!"
/bind N move left
Result: When you press N, your character will move to the left and say "Going left!"
The NW servers are currently down, so unfortunately I can't test this. Hopefully it works (and helps).