OK, I was asked to create a trigger that when someone moved in a direction would see it and copy that direction to a standard command/macro. This is simple enough, I created it and the trigger worked when setting a command (I know I could make this trigger a lot more compex, but for now this is appropriate):

Trigger content (using regex):

leaves (north|northeast|east|southeast|south|southwest|west|northwest)

-- Now, with regex, this will trigger every time it see's 'leaves <direction>'

e.g.

Bob leaves north
Tommy leaves south
(both the above activate the trigger)

Bert leaves headstand
(does not activate the trigger)

Now, in order to set a command I can use the regex %n concept. In brief, each % equals a regex match: %0 is the entire string, %1 is the first item in ()'s and so on.

e.g.
bob leaves north
%0 = 'leaves north'
%1 = 'north'

So my trigger action to set a command is:

command follow %1

This works.

Now the problem, the person wanting the command wanted it to be all done client side: The client has the option of setting client side commands called macros these are activate by using the / prefix. (/macrolist lists all your configured macros, /macro <name> = <content> creates a macro, /<name> uses the macro).

So, the trigger action needs to be changed to set a macro rather than a command

New trigger action:

/macro follow = %1

Now, when we get:

Bob leaves north

the action should be:

/macro follow = north

But instead, the macro follow is literally set to %1.

/macrolist
...
/follow = %1

In short, regex results are not sent to the creation of macro commands (I don't know if it's a bug, or something to do with the '/' at the start of the action).

A related question, could we get a variable that equalls the party leader?