Hi Johan,
If you just want to display it in a "display" field. Where it asks you for the value (just under the word Text) place st.GetValue(). Assuming st is your stringtheory object. Don't to tick allow xHTML if its HTML (or even unsafe xHTML - if its a bit fancy).
Thats a start, if its like a whole page of HTML, we'd need to do things a little differently, but a snippet of HTML should work ok.
Regards
Bill