If the alternate versions are part of the same font, then each version has its own unique unicode number. It will be something like ᅜ You will need to enter this in the HTML script. Charmap.exe is one way to get a unicode number for a given glyph. In Windows 7 charmap.exe can be found in: Start » Programs » Accessories » System Tools » Character Map. If the number unicode number is:
3721 (decimal) you type ຉ
04A7 (hexadecimal) you type &x4A7;
The semicolons are important, so please don't forget to include those in the script.