I found out HTML isn't a available out-of-pocket option in the AppointmentItem-Object.

Then i found the following answer with code from the user PGilm here (

Having your formatted text in Excel you can copy it to an AppointmentItem (based on the workaround presented here

CodePudding user response：

If you copy the html formatted text to MS Word you can save the document in RTF format. This rtf document you can either rename to .txt and add the rtf encoding to the vba editor or you read the file with vba.

Based on the proposal here: