Changing ellipsis display for invisible lines?

[Uwe Brauer]

>> Regarding Re: Changing ellipsis display for invisible lines?; Aidan Kehoe <kehoea at parhasard.net> adds:

   >  Ar an ceathrú lá is fiche de mí Meitheamh, scríobh Uwe Brauer: 


   > (set-glyph-image invisible-text-glyph [string :data "\u2026"])


Thanks, but...
First of all this is 21.5 only right? At least in 21.4 it
just displayed u2026 :'(.

Now in 21.5. This setting displays a stylish ... 
Instead of the usual ...

It seems that the command is what I am looking for but again
the string I want is 

[+]


Instead of 

...
So the following worked nicely in 21.4 and 21.5 
(set-glyph-image invisible-text-glyph [string :data "[+]..."])

thanks

Uwe