calculation of curtain walls' area in zone's stamp

[Anonymous]

Hello,
does anybody know if/how could we show in the stamp of a zone (see attachment) the area of the a curtain wall which is in contact with the zone, exactly what we do with the windows (apart from the solution that we can design at the same place a simple opening)?

Thanks in advance

[Christophe Fortineau]

The zones can target curtain walls with "Linked 3D Element" property (into general property)
The curtain wall area can be found but I don't find the way to do this
Probably with a personnal property by an expression (I've seen you work with AC22) ?