I don't see why you don't like the workspace. What does "One module - one DLL" mean?
For example:
Project hold 12 modules (1 main and 11 DLL called from main).
Each module hold near 50-150 source files -> summary 1000+ files.
Each module hold opened 5-10 files -> summary 50-100 files.
On activate a some module I must doing search for files of this module (one file from 50-100 files).

Each module being builded with using makefile.
Worspace is inconvenient to use in this project.
Isn't this what CodeSnippets is for?
Create a catagory for each workspace or project. Under the catagory, create a file link to each .cbp file (right click/edit/properties/link target).
Thank you. This method looks like. I try use it.