Here's a good regex reference:
http://www.regular-expressions.info/reference.html
In regular expressions, the following are "special" characters that need to be dealt with in a particular manner:
[\^$.|?*+()
To search for any of these, you need to put \ in front of them to supress their special meaning.
With your string as follows:
Code:
">ABC Amber LIT Converter http://www.processtext.com/abclit.html ABC Amber LIT Converter http://www.processtext.com/abclit.htm
...you can try searching with the following regex:
Code:
">ABC Amber LIT Converter http://www\.processtext\.com/abclit\.html ABC Amber LIT Converter http://www\.processtext\.com/abclit\.htm
...that should find what you're looking for. Note the \ character in front of the . to search for the period itself. Also note, in the simple .html file I created to test it, calibre converted the "> to "> when generating the code in the regex wizard/tester - you might need to fiddle with that part a bit depending on your actual source, it might be a bit different if it's not a .html input file.
Cheers
The REAL Joe