Hi Phillip,
Mathcad Prime 3.0 Express does not support region tags. Those tags you are talking about are used in versions of Mathcad 14/15. In Mathcad Prime Express 3.0 version tags are not used to transmit/receive data with Creo, you must use the tab "Input/Output" and then select "Set input/Set output". Of course, Creo 3 support Mathcad and Mathcad Prime analysis.
