showing sheet numbers on isometrie

hi all,

we wonna show the max. sheetnumber of the pipeline on the drawings, so you can see this is iso 1 of 3 isosheets.

if i open an iso in isometrics i can found under drawing tag data the information "no_sheet" that shows the highest sheet number of the pipeline. But i dont found this data field in the text node editor.

Where i find this data field no_sheet in the schemas and how can i add to the list in text node editor.

Here you can see unter point 17. this like we wanna get it: https://communities.bentley.com/products/plant/w/plant_design_and_engineering__wiki/23069/how-to-format-number-property-in-isosheet-name

Thanks,

Markus