...
Child, HTMLtextObject,
MUIA_HTMLtext_Contents, "This is a <b>Test</b>.",
End,
...
But don't forget, that HTMLtext.mcc uses some more memory and is
slower than TextObject and it doesn't always make sense to use it.
C++
If you want to use HTMLtext.mcc using C++ please have a look at "dev/mui/MUIPlusPlus.lha" written by Nicholas Allen.