Create custom annotation for Chinese hamster (Cricetulus griseus)

Hi, I’m new to both learning and running NGS data analysis tools.

Most of the packages in bioconductor require same format of annotation.

But looking at [AnnotationData package],1 there is no public annotation package for Cricetulus griseus.

I want to create a new annotation for Cricetulus griseus (CriGri-PICR)(CriGri-PICR can be accessed in Ensembl, not in UCSC genome browser).
If I have to create a custom annotation for bioconductor usage, can you give an advice for creating a new annotation?

Thanks