Ottava brackets abuse

[Helge Kruse]

Hello,

I need to write something that looks like ottava brackets, but must not 
affect the pitch. With _#(set-ocatavation 1)_ I can create a bracket 
that yields to _#(set-ocatavation 0)_ and I would also change the text 
to i.e. _\set Staff.ottavation = #"Pincé"_ after several measures.

But how do I keep the pitch for these notes?

Regards,
Helge