parenthesizing only part of an articulation

[Urs Liska]

Hi list,

I have something like
c2-_
and need to enclose the 'staccato' part of the articulation with 
parentheses (as this is an editor's addition). Unfortunately I didn't 
find a way to do this. Also it doesn't seem to work to add the -. and 
the -- separately.

How could I achieve this?

Thanks in advance
Urs