I am not visualizing what your saying. However, sure sounds like you can use your mouse, highlight the offending characters/text (including that which spans multiple lines) then hit ctrl-r (which brings up the search replace dialog box).
Do your replace of old with new as desired.
If you set the "regular expressions" check box, you can use expressions such as ^p in either the search box or replace box (or both). Do a help on regular expressions for more details of what symbols are available and what they mean.
If you like the effect you get with your replace, do this again only this time on this time first click "macro" "record" fill out panel as desired. do your replace and then click "macro" "stop recording". Depending on how you filled out that panel, you now have a key that when pressed will do the global replace for you.