Does anyone know how I to create empty environments in Guile Scheme (preferably 1.8)?

The task at hand is well known: the user of an text editor can input complex commands with parameters (a little bit like in Emacs). Now I would like to read these commands as single procedure calls with its parameters as an s-expression. But then how do I evaluate it in a special environment where only the editor commands are available by default?

The (null-environment 5) gives me an empty environment but how should I insert the editor commands? Last time I checked (that was about some years ago when I didn't really need it) I found some C only routines but maybe I mixed them up with the UNIX process environment (variables).

How do I create a hygienic algorithmic text editor language within the Algorithmic Language Scheme?

Perhaps it's even better to give access to the usual Guile top level environment ...