How to add a tag parameter to an identified Portrait Dialogue questionnaire URL and then shorten the URL

For the expression function AnswerFormURLEx (of a defined number of parameters) that returns a string containing a URL to an answer web page

string AnswerFormURLEx( integer UrlType, integer QuestionnaireID, integer LayoutID, integer BroadcastID, integer DialogID, bool Scramble, bool NoTrack)

an additional parameter can be added when characters &_ precedes the name of this additional parameter.

When the original URL should be shortened additionally use the ShortenURL expression function.

For example:
Base expression function with values:

«#AnswerFormURLEx(1, 1235, 1272, -1, -1, FALSE, TRUE)»

can be shortened and have additional parameter when it will be constructed like this :

«#ShortenURL(AnswerFormURLEx(1, 1235, 1272, -1, -1, FALSE, TRUE) + "&_WT=TEST")»
UPDATED:  March 23, 2017