[R-sig-ME] adding objects into "glmerMod" fits

[Vito Michele Rosario Muggeo]

dear all,
for some reasons I would like to add some new components (vectors,  
matrices) to a "glmerMod" fit. I am not familiar with S4, so borrowing  
from S3 classes my first tentative was

o <- glmer(y ~ ..)
o at new<-1:3

But it clearly does not work. Is there any solution?
thanks in advance for your time,
best,
vito