Strugging with Commands

I am struggling to write a command which edits a model, rather than the command instance itself. I am trying to do it this way since the model class and description may change whereas the command class does not. PREditUser-asComponent | component | component := self model asComponent. ^ component addValidatedForm: (Array with: self saveButton with: self cancelButton); onAnswer: [ :value | [ self execute ] on: Error do: [:err | ^ component errors add: err. ]. value storeOnDB. self context: self answer "<<<does not work" ]; yourself. The problem that I am having is that the standard onAnswer: for commands is implemented by the containing Contents Widget somewhere else and I cant see any way of overriding it. Thanks in advance for any ideas Keith