How to configure Run/Debug Configuration for a library that runs using a prebuilt executable?

Hi,

I have a library defined using cmake, as normal. It compiles as expected.

The library is written for use with a pre-built executable for which the source is not available. In other IDEs I have the option to choose the executable I wish to run in order to debug my library in the IDE, but I cannot see how to do this in CLion - you only seem to offer Application Run/Debug configuration for executables that have been built in the development environment using cmake.
Is there an option for this somewhere? Maybe it is configurable via CMakeLists.txt? Can you help?

Thanks,