Eloqua Native Integration field mapping - custom fields

Hello,

We are using Eloqua and its native integration with MS Dynamics CRM. Through external calls, you are able to map Eloqua standard fields to MS Dynamics fields. Unfortunaltely, only standard fields are visible

I have always been wondering, whether is it possible to map not only a standard field, but also a custom object field. I checked it up and down, back and forth and I do not see a possibility to do that. Am I missing something?

Thank you!