Technically this could be done, but not using a similar command to "associateplayer" and it will require some scripting effort.
Your best best is getting the entities to react the same to their activation level. The activation level is a parameter each entity has during the game. By default the activation level is zero, but it can be changed during the game so that the entity can react to it. For example, the remove doors use the activation level to open and close when a switch is pressed - check that script out to see what it's doing.
Anyway, getting back to your associated entities. What you'll need to do is set up the script of both entities so that react according to the activation level, something like this:
Quote: ":activated=101:movefore=1
:activated=102:rotateiy=2
:activated=103:rotateiy=-2
:and so on...."
Then you need to set both entities to the same activation level during the gamne. This can be done a number of ways:
...by setting them as mutual targets:
Quote: "In Char02's script
:always:settargetname=Char01:activatetarget=101
In Char01's script
:always:settargetname=Char02:activatetarget=101"
...by setting them as each others "If Used" entity (i.e. in the editor type the name of the 'other' character in the character's "if Used" field):
Quote: "In both character's scripts
:always:activateifused=101"
...by using a useful proximity condition (entities must be named in each others "If Used" parameter):
Quote: "In both character's scripts
:always:activateifusednear=101"
The second method is probably the easiest as it only requires 1 script.
The thrid method will only work if the entities are within 80 units of each other.
I hope this helps.
Ched