This is a struggle on almost all of our plan & profile sheets with construction notes/labels. The inability of Civil 3D labels to have a FIELD reference inserted into the label itself. We use Multileaders with FIELDs all the time to reference sheets in the sheetset manager. The structure label for a pipe network has the ability to pull all the information from the pipe network, but it can't have a FIELD insert to reference a sheetset that has a specific detail of the structure you are labeling. Please make Civil 3D labels capable of inserting a FIELD into the label in edit label mode.