[R] multiple error strata in aov

[Murray Logan]

I am trying to perform a model 3 ANOVA for a 2 factor (say factor A and 
factor B) anova in which factor A is fixed and factor B is random. 
 Therefore, the error term for the test of factor A should be the A:B 
interaction term and the error terms for B and A:B should be the model 
residual (within) term.  I have tried to work out how to specify such 
error strata using aov, however, I have had little success.  Is there a 
way to specify just the interaction (A:B) as an error term using Error() 
within aov or provide a list of error strata.  
Ideally as Error=list(A="A:B",B="Within", A:B="Within")

In addition, I have tried using lme to perform this function, but again 
without much success.

Can anyone offer any ideas

Ta

Murray