Copy your model to "C:\MentorGraphics\PADSVX.0\SDD_HOME\hyperlynx\Libs" or add the path where you have it to the libraries.
Place a transmission line in Hyperlynx. Double click on it. Change it's transmission line type to Connector. Select your model from the list in the next tab.
Hope this helps.
many thanks... it works... I didn't know I have to change the transmition line type as a connector
Great! and thanks