Which COBOL product are you using?
You mention that you have several Forms so I am assuming that this is Visual COBOL and this is a Windows Forms project, is that correct?
You can create either a COBOL class or a COBOL program in which your files are defined and then you can invoke methods in this class or call entry points within the program which will handle all of the file i-o.
You can place this class or program directly within the same project as the form programs or you can create a new project and place the file I-O modules there, in which case you can add a project reference to this new project within the references folder of the calling project or projects.
Is this what you are looking for?