Notepad

In the search window, check the regular expression box, and type this in the search area:

icon=".[^"]*"

Explanation: we start with the normal text icon=" and we end with the final hyphen "

Therefore remains: .[^"]*
The dot means any caracter and the star means as many times from zero to infinite (or to the end of document or whatever).
But we don't want to go to the end, we want to stop at the first hyphen we cross. To tell something about specific caracters, we put them into square brackets. And to say don't catch any " we put a ^ before it.
Beware, the ^ hasn't the same meaning when it is inside brackets and when it is outside. Inside brackets it means no but outside it can also mean starting with