Inserting text where the cursor is placed

[captain_torche]

I'm adding a new button to wymeditor, which opens a list of items, and I'd want some text to be inserted where my cursor is, when clicking on the items.
I tried the 'paste' function, but it creates a new paragraph at the end of the text.

Is there a function I could use ?

[captain_torche]

I wasn't aware the question was so difficult
Is there a way to get the entire list of built-in functions ? (Like paste(), plus eventually others ?).

Thanks a lot.

[captain_torche]

I apologize for this, but I haven't got any clue to do the trick.
A function that does this must exist, but I don't know its name.
Is there a list of all the functions somewhere (Like paste() and so) ?
This would be a great help.
Thanks.