Hi Massimo Taroni,

In Training/Documentation Library you have three Allplan Label Styles Tutorials (version 2019). To access it you need Service+ account (reasonably priced yearly subscription) for Allplan Connect.
In the same library you also have Allplan 2019 Engineering Tutorial, which is available without S+ account. In that tutorial find Exercise 8: Custom Title Block. It's basicly the same principle, using same tools.

Hint1: If you want to save one Label Style for several scale factors, than use DefFol function to Define Foils for each scale range.
hint2: Use Allplan201x/PRG/AttributManager.exe to find appropriate connection from Ifnr to attribute name.