I think so. Try this...
Open up ECLIPSEDIR/plugins/com.slickedit.windows.libs_3.5.1/slickedit/macros/seldisp.e in Eclipse with the SlickEdit editor. The path might be slightly different based on what platform you are on, and what version of Core you are running. Find the function _preprocessing_supported...it should be about on line 357. Change the return statement in that function from what it is:
return(lang=='c' || lang=='cs' || lang=='pas' || ('.'lang==_macro_ext));
to something like this:
return(lang=='c' || lang=='cs' || lang=='pas' || ('.'lang==_macro_ext) || lang=='mylang');
where 'mylang' is the p_LangId value for your in house language. Now load the macro with F12. Now if you open one of your in-house language files and go to Display > Selective Display, is the "Preprocessor directives" option enabled?
- Ryan