Use a paragraph and a text area with visibility condition on both using a flag value.
On button click use refresh this section and run an activity to set the flag value and also use Property-Set-Stream method to fetch the contents of the paragraph rule into property assigned to the text area.
Method Parameters :
PropertyName : <<property reference in which you want to get the paragraph content>>
Stream Class : "Rule-HTML-Paragraph"
Stream Name : << paragraph rule name>>
But I think we will not be able to write it back to the Paragraph rule.