Have you tried actually running the replace operation? It should be OK. Word will select the characters preceding the first paragraph end mark, but they will be replaced with themselves, i.e. they won’t be removed (this is done through “\1” in the Replace With box). I successfully tested this wildcard pattern in Word 2007 on the sentence you gave as example.

Note that you can always undo any replace operation through “Ctrl+Z”.

Also note that depending on your system locale and the active list separator, the semi-colons within curly brackets {1;3} might have to be replaced with a simple comma {1,3}.