Leverage Marketo custom objects

Hello,

We use Marketo (amongst other things) for our product registration process. We capture the data in custom fields for "latest product registration" and "history product registration" for previous registrations.

We are not using custom objects here since one of the product registration steps is to check if that product wasn't being registered in the past (using 3rd party server).

The thing is, is once the product has been registered we would like "attach" more data to it (like: product description, model [based on product number], etc.).

Is there any way to push this "external" data into the custom object so it will be related to the specific registered product?

Thank you in advance!