How do I attach Carriageway / Paved Shoulder string as an associated string while designing vertical profile in "Element Method".

How do I attach a carriageway string as an associated string for reference while doing the vertical profile of service road using Element Method ? In Quick alignment method, it is quite simple - Profile Surface Details - Advanced - Display Associated String - Select model and then string name. By this I can get the carriageway string of main carriageway as a reference which I need for designing the profile of parallel service road.

In Element method, the option of "Add collinear profile" only allows to attach a triangulation string.