How to express words such as "Haha" in a much more formal way?

Question

parthkohli · Answer

@dta255 So there. Haha.

anonymous · Answer

To be honest, the usual means of conveying laughter would be through imagery and wording. For instance, they write something like "roared and writhed in absolute delight".

parthkohli · Answer

Will I say that I am roaring and writhing in absolute delight when I laugh?

anonymous · Answer

Yeah, you mean like adding the word "laughing"?

parthkohli · Answer

Let me get a lot more concrete. 
If you look at my first reply—"So there. Haha.", you'd get the idea of what I am looking for. 
I want a substitute for 'Haha.'

anonymous · Answer

Yeah, roaring and writhing in absolute delight is an adequate substitution for just "haha"

parthkohli · Answer

"Yeah. *roars and writhers in absolute delight*."
Does that $\textbf{really sound appropriate?}$

anonymous · Answer

Yeah if you are doing something say writing a short story

anonymous · Answer

But as for forums like this one, it won't really do

parthkohli · Answer

Oh. I see it very well. Thank you!

anonymous · Answer

No problem, anytime.

parthkohli · Answer

I must admit—you are a great help in the Writing section. A majority of us live in the Mathematics group; admirable to see a person working hard for the minority.