Create SAP RFC iView with a structure as import parameter

Hello All,

I'm creating a SAP RFC iView from Portal SAP 7.4.

I try call a RFC that have as import parameter a structure with various fields, but the portal recognizes the structure as string field, then I cannot fill the fields values, and when  I do a preview the iview, the following error occurs:

And only is possible select a output object.

Exists any way of receive a structure or a table as import parameter?, and as output parameters more of a element?

Thanks for your collaboration.