This might help a bit: 

http://www.w3schools.com/jsref/jsref_match.asp

http://www.w3schools.com/js/js_arrays.asp

The match function returns an Array as your result. The [0] slot is always what you searched for. Any matches happen in later slots.

So in your example you always are only expecting what's in slot [1], so you'd need to add the following:

                     mytext ="123|xxx|200|sss"
                     tempMatch = /\|(\w*)\|/.exec(mytext);
                     temp = tempMatch[1];
                     $('.MyData input').val(temp);

At least I think it would be. I don't have something up to test right now. :)