Field within hidden text

When creating hidden text, the text is usually entered within a box on the field definition window. Is it possible to enter another field (a database field in my case) within this box? Or by any other means to include a field within a hidden text field?

EDIT:
A related problem occurs in hidden paragraphs. When a conditional field is nested in a hidden paragraph, the paragraph is always visible.

The second behaviour (the edit) has only arisen in v6. 5.4.7.2 works correctly. 6.1.0.3 works neither with Firebird or sql. I would consider this to be a bug.