Yet for the purposes of Pali texts I would advise specially adapted
fonts, found at http://zencomp.com/greatwisdom/fonts/
especially CN-Times,
since usual Unicode font doesn't have retroflex letters.
CN-Times can be converted correctly to HTML, and most letters are converted
directly to the simplest code (for example, aa to ā).
Specifically for the purpose of HTML conversion I have compiled a
MS Word macros that converts a CN-Times HTML retroflex letters codes (for
example, ṃ) into font-free codes (for example, ṃ).