nned help on printing strings matched by an ANTLR parser rule

Hi Friends

I need some help on how to print the input string in an input file
matched by a parser rule in ANTLR

The parser rule can contain many subrules and tokens

The rules can be of the form (~SEMI *) LFPAREN header; etc

I want to extract the string in the input file which matches a
particular rule like above.

Any help is greatly appreciated

Thanks in advance
Mabel
.