The "manual" way to enter pin labels... With the shape selected, open shapesheet and scroll to Connection point section. Using dbl quotes, enter label text into the D-Cell. Also, the pin type C-cell entry may be changed here if desired. DO NOT edit the pin label directly as this will clobber the link to the connection point D-Cell.
When this code was written, there was no anticipation for high pin counts, thus manual entry was OK method. It could be automated if, say, an Excel file existed which contained the desired info.