The Rocket Enterprise extension offers editing support for COBOL (including native, native Object-Oriented COBOL, .NET COBOL and JVM COBOL), PL/I, Assembler, BMS, JCL, and IMS code.
You edit source code in Visual Studio Code by opening either individual files or by opening them as part of a folder. Visual Studio Code does not have a project system.
To edit your sources:
Visual Studio Code offers colorization of the code in the editor.