[General] (Extended) Ability Tooltip change via gui function

[SpiritTauren]

Does it even work (I mean the blizzard's gui line)? I've tried various approaches, and the ability's tooltip never changes.
The same feature works for my item tooltip updates just fime.

call BlzSetAbilityExtendedTooltip( udg_NAME[1], LoadStringBJ(1, 1, udg_HashtableNAME), 1 )

Anticipating the question, I load a string.

 

[Uncle]

The Indexes start at 0. So ability level 1 = 0, level 2 = 1, level 3 = 2, etc...

A lot of the new functions don't work yet but I'm pretty sure this one works.

 

[SpiritTauren]

The Indexes start at 0. So ability level 1 = 0, level 2 = 1, level 3 = 2, etc...
A lot of the new functions don't work yet but I'm pretty sure this one works.

Thank you.
I've tried with 0 as well even before posting. (In fact, assigning several lvls, trying loading strings from hashtables, or typing them directly in the string field.). At first, I thought the reason was the ability being listed in a spellbook. But it didn't matter.

Then I tried this:

call BlzSetAbilityExtendedTooltip( udg_SpeechDialogOption[1], ( SubStringBJ(BlzGetAbilityExtendedTooltip(udg_SpeechDialogOption[1], 0), 0, 0) + "NEW  EXT TOOLTIP" ), 0 )

,

and it worked. So, setting an ability tooltip to concatenated strings works, as long as they include reference to the initial tooltip, even if it's an empty substring (0,0).

Update 2: I re-tried setting it to a simple string... and it worked. WTF I could swear to God, I used level 0 as well earlier today and it didn't work before. Strange...
So, SOLVED.