vbCode Button Functionality Mod?

[Clarity]

I've been looking for the hack or template mod/JS (this very board seems to be running it), that modifies the functionality of the vbCode buttons a bit.

On my stock 2.3.0 board, you cannot highlight a word in your message field, hit the 'I' button (as an example) and have it italicized (as per my 'I' example, bold and underline work as well). Hitting the button only appends the appropriate vBC at the end. This board does exactly what my users are asking for, I can finish this sentence without any code, then go back and highlight 'sentence' with my mouse, hit the U button, and it will be underlined.

I've spent the last hour looking for such a hack, but have come up empty, came here to this area to ask someone to make it, and realized as I was posting that it exists somewhere.

Little help? Thanks in advance. I've posted this both in Hack and Template Requests simply because I don't know which way it's handled. I've seen button functionality mods in both.