I’m new to this, so I may be way off.
Why not set up a counter for your sections and example? The following appears to work:
[counter:section]
:!part: {counter:part}
Section {counter:section}
Part {section}.{counter:part}
Part {section}.{counter:part}
Part {section}.{counter:part}
Section {counter:section}
:!part: [counter:part]
Part {section}.{counter:part}
Part {section}.{counter:part}
Part {section}.{counter:part}