Need Help for Syntax HighLighting

[Hans Lehmann <hans@xxxxxxxxxxxxxx>]

Hello,

I am looking for a string- or RegExp-pattern allowing to highlight the 
comments in the proprietary language LIPA. The comments in LIPA are 
enclosed in curly brackets. Here an example for a command line:

INP(16);    { First summand (s1 ∈ ℕ) is entered » stack_1 }

My aim is to highlight the text between the curly brackets - which means 
without the brackets.

I tried:

Comment:
  from { to }     <---- that works, but includes the brackets
  between { and } <---- that doesn't work at all

and tested regular LookAhead and LookBehind expressions like

  match /(?<=\{).*(?=\})/

but they didn't work as well although they work with the Gambas 
RegExp-class.

Can anyone help?

With kind regards

Hans