Are you using the Dowel Pins from the Toolbox?
Were the pins downloaded from McMaster-Carr?
Seems like a standard toolbox part.
When you insert the part from toolbox, you have the option to add a new part number & description to the part.
If it is an already added part, you can RMB click on the part and "edit toolbox part", then edit the part number there as shown
This will populate in your BOM
that answered my question.