Use an If widget and put the text with the link and the Popup Editor widget in one sentence and the text without the link in the other sentence.
http://www.outsystems.com/help/servicestudio/9.1/index.htm#t=Web_User_Interface%2FPresent_Conditional_Contents.htm
http://www.outsystems.com/help/servicestudio/9.1/index.htm#t=Web_User_Interface%2FPresent_Conditional_Contents.htm