Eclipse Debugger Usage nn Windows

[NonStopGuru]

Hi,
currently I am working on a Windows project in C using Eclipse CDT, gcc C compiler and the Eclipse debugger. Starting programs in debug mode works. I have encountered 2 problems, maybe someone here can help me:

1. How do I programmatically invoke the Eclipse debugger? In ancient times I worked with Visual Studio and remember the Windows function DebugBreak(). I tried this, but it did not work. My project internally spawns several processes and I need to catch one of them in the debugger at a certain point. How can I achieve this?

2. The project uses several source modules from other projects. I use the Eclipse link feature (i.e. use the "Add file", "Advanced", "Link to file in file system") features in Eclipse. The project builds ok. I can debug and step into the "linked" source files. But setting breakpoints in these files is not working. The breakpoints are simply ignored. I am also using the Eclipse debugger for an exotic platform (HPE NonStop) using cross compilers. In this scenario breakpoints in "linked" files work, so it does not seem to be a "cannot be done" kind of limitation. Is there a setting to enable this?

Any help is appreciated, thank you very much.
Kind regards
Werner