So there is one extension you want to skip; but how many different ones are there to include? If a small number, the obvious solution is to exclude the one you don’t want by including all those you do want.

Unfortunately AFAIK it is not possible to exclude certain file types from Notepad++'s “Search in Files” feature. But you could use grepWin for that. It can be customized to open a search result in Notepad++. Since it is even possible to call Notepad++ with the line number it should jump to as a command line parameter, you will feel very comfortable with this solution.

grepWin’s homepage is >>> here <<< and it can be downloaded >>> from here <<<.