OK,

So I made a custom costume... a new Sector 31 agent who only ever be seen through Pop-up dialogues. (Creepy!)

OK, anyways, she's a babe. But I can't select her for the pop-up dialogues.

So I made a map and placed her on it, then tried to select her in the map as the person for the dialgoue box.

That didnt work either.

Can this be done? If so, got directions for me ?

What kind of dialog box?

If it's just a standard pop-up, you should be able to select it from the default tab, and filter the list to the character's name. It's sorted alphabetically, so it might get lost in the list.

Placing the character in a map is used as a target for a Contact objective - or for ambient characters, where you can fill out their default box for some 'chatter'.

If you made a custom costume character, you ought to be able to assign it for the image in a straight up pop-up dialogue box. Click the button that assigns the dialogue box contact, and then look under the Assets tab -- it should be a MONSTEROUS list of NPCs Cryptic has already made, but if you search in alphabetical order, you WILL find your costume name and be able to assign that character as the dialogue box face thing.

OK, thanks for confirming that what I was trying is correct thing.

Time for a bug report.