Remove extra enter mark by script

You get the problems with changing styles because of the \r that's replaced. So you should leave alone the first \r in a series  and remove any following ones. You can do this with the following query:

Find what: \r\K\r+

Change to: <leave empty>

Do you mean find:

~b~b+

replace with:

\r

You can use this predefined search in ID out-of-box.

or what do you mean???

(If not this, sceenshot with visible hidden characters and more informations please.)