Want to improve this question? As written, this question is lacking some of the information it needs to be answered. If the author adds details in comments, consider editing them into the question. Once there's sufficient detail to answer, vote to reopen the question.

I am trying to analyse my data but I am unsure if repeated measures ancova is the way to go. I have a variable named "A" measured in three different conditions "1", "2" and "3" (the sample size between groups is unequal). I also have a continues covariate measured just once in the first moment.

My R code until now is:

Rmancova <- aov (A ~ condition * moment * covariate + error(id/moment)

I did try ezAnova in R but it didn't help me as it doesn't incorporate covariates yet.