Thanks heaps Paul. I tried your script. It created a new html file But with the same content.
<br> was not replaced by <br><p></p>. I was able to find another method to do search and replace in html files. I opened them in notepad and "sendkey"ed my requirement.

This is the macro i wrote.

sourceHtm = Dir(SourcePath & "*.htm")
If sourceHtm <> "" Then
RetVal = Shell("NOTEPAD.exe " & SourcePath & sourceHtm, 1)
AppActivate RetVal
SendKeys "^h", True
SendKeys "<br>", True
SendKeys "{TAB}", True
SendKeys "<br><p></p>", True
SendKeys "%a", True
SendKeys "%{F4}", True
SendKeys "%fs", True
SendKeys "%fx", True
End If