Showing different text in confiforms registration control depending on entry values

[Peter]

I would like to adapt the the text shown in the registration control of a confiforms app depending on an item to be registered. If somebody selects "Lecturer", the text in the registration control should show "Blocks where you would like to teach", if somebody selects "Professor", the text in the registration control should show "Blocks where you cannot teach". 

I know how to do this with a field, but a field is always rendered as input, I could accept, if the field was rendered as plain text.