R help - Jun 2004 - modifying a glm object

I need to modify a glm object directly, by assigning new values
to the fitted parameters.

(i.e. the canonical parameters stored in object$coefficients 
and returned by 'coef').

Is there a "safe" way to do this, e.g. so that 'residuals' and
'predict'
give the correct results for the new model?

thanks
Adrian Baddeley