This is not yet possible. When Hiawatha used OpenSSL, I couldn't get it working due to the incomplete and horrible documentation. With Hiawatha 8, I switched to PolarSSL, which is very well documented. However, PolarSSL doesn't support
SNI [en.wikipedia.org] (which is what you are looking for). I asked the PolarSSL developer for SNI support and he promised me to build in SNI support in the next PolarSSL release (version 1.2). Soon after that, Hiawatha will have SNI support as well.
You could also ask the PolarSSL developer for SNI support. It could help to get it sooner