All you need to do is delete the
Code:
<i>26 Using Your Brain</i><br>
references.
The stuff with <A name=....> gets deleted as part of the default processing, so you don't need to particularly worry about that.
The regex should be something like:
Code:
<i>\d+\s*Using\s*Your\s*Brain\s*</i>\s*<br>
There are alternate tools like Cybmole mentioned, mobipocket creator, etc which should be able to do a basic conversion as well, perhaps with less pain and suffering on your part. That said I haven't tried them, so can't really comment.