Creating a new BB code button

[elitemerlin]

how would i go about doing this...i will pay for the instruction if need be,

i want a button (with a corresponding image of course), that when you highlight something, and click this button it would create

highlighted_content_here

it would entrap the content with hidden and code tags. Thanks in advance.

[tminus]

how would i go about doing this...i will pay for the instruction if need be,

i want a button (with a corresponding image of course), that when you highlight something, and click this button it would create

highlighted_content_here

it would entrap the content with hidden and code tags. Thanks in advance.
I haven't used it, but there is this spoiler BB code mod:
https://vborg.vbsupport.ru/showthread.php?t=112376&highlight=spoiler+bb+code
It adds spolier BB tages that hides the text and you click the "click to show button" to show it. It is also going through a revival, a new modder is taking over, dismounted, so it should get updated soon. Supposedly some users have it working on 3.6.5, but I can't say for sure if it works.

[Dismounted]

Yes, that is true, I am taking over that mod, and it will be released under 3.6.x.