The best you can do, if the notes you want to replace have the same characteristics, is to copy one of them to the Find menu, move to the beginning of the staff, and Repeat Find (F3).  You can edit some things out of the Find window, if perhaps you want to find all notes of one duration, but you don't want to limit your search to the ones of a certain pitch.

The Find will highlight each occurrence, one at a time, and you can simply press the space bar as you arrive at each note you want to change.  If the note is dotted, you'll need a dotted rest, but you should be able to use the Persistent Note tool to make all the rests you enter also be dotted.

I think version 2 of NWC might have a user tool for global search and replace, but I don't have time to check just now.  If it's there, I've never used it.  In any event,it won't work in NWC version 1, I'm sure.