How to find and replace with same character count with no affect on Bullets?

I need help to replace with identical character count words within a bulleted paragraph without change existing bullets.

However, replacing "AUG:" with "SEP" in 2nd bullet affected sub-bullet (4.1) of 4th bullet; "4.1" now appears as suffix to line of 4th bullet; as if backspace typing was applied to bullet 4.1.