Script: Add henchman
Creator: Not sure
Description: adds the NPC as a henchman. take note that this is best used 
in an ActionsTaken in the dialogue tree.
NWScript:
void main()
{
SetAssociateListenPatterns();
// * Companions, come in, by default with Attack Nearest Enemy && Follow Master modes
SetLocalInt(OBJECT_SELF, "NW_COM_MODE_COMBAT", ASSOCIATE_COMMAND_ATTACKNEAREST);
SetLocalInt(OBJECT_SELF, "NW_COM_MODE_MOVEMENT", ASSOCIATE_COMMAND_FOLLOWMASTER);
AddHenchman(GetPCSpeaker());
}

Notes: In the NPC properties, set his scripts tab to this:

nw_ch_ace
nw_ch_ac3
nw_ch_ac4
nw_ch_ac6
nw_ch_ac7
// blank \\
nw_ch_ac1
nw_ch_ac2
nw_ch_ac5
// blank \\
nw_ch_ac9
nw_ch_acb
nw_ch_acd