I'm a bit confused by your post. groupthis is actually two commands, not one, and the way assignment works is actually the other way around! I suspect that you are mangling up a standard method of recording a group, without fully understanding how scripting works. E.g. common init line is:
alphaTeam = group this
is the way to assign the variable alphaTeam to the group of the character whose init field that code appears in. That group could be referred to in scripts as alphaTeam. This has nothing to do with labelling the group differently (sometimes people call assigning a variable for an object or group "naming" it, but this isn't the same as giving it a textual name label). For this, you'd use:
(group this) setGroupId ["Alpha Team", "GroupColor0"];
Hope that makes things a bit clearer for you...