[h-e-w] Adding a new-line in replace-string

[Vaclav PEROUTKA]

Hello,

I have ntemacs version
GNU Emacs 21.2.1 (i386-msvc-nt5.1.2600) of 2002-03-19 on buffy

I am trying to cut single long HTML line into more short lines. How
can I add \n in the front of each <h3> label ?

I tried M-x replace-string ENTER ... but C-q does not work in the
minibuffer. If I press C-q nothing except beep happens and C-m starts
the replacement.

Even C-^ (C-shift-6) does not work for me.

And vice-versa - how can I delete empty lines in some file in NTEmacs by 
replace-regexp ?

Thank you in advance,
Vaclav