Setting the SugarCRM Lead Owner from Marketo

We're using the SugarCRM connector and I've been told by SugarCRM support that the "Owner" of a lead is not a Lead record attribute, therefore, it has no corresponding field that can be set with a value from Marketo forms. 

Does anyone have any tips on how I can assign an owner to a lead record through a Marketo form (default value in a hidden field) and make this pass properly to Sugar, so the Sugar lead record has the Owner value?