A delimiter can be added, to the display of a Number (Part Number, Project Number, Document Number etc.) created by Auto Number. This will not change value in the system, but only how the Number is displayed.
Splitting of an Auto Number, is accomplished through SOLIDWORKS Manage Administration Options.
Select Numbering Schemes from the Advanced Module.
Then Edit or Create a new Numbering Scheme.
Then Edit the Auto Number
From the Numbering Scheme Item, Check Split Number and select Configure…
Add a Delimiter.
Define the Delimiter and the location of the Delimiter. As the below graphic illustrates, the location is defined by a numerical value.
If required, multiple Splits can be added.