User Defined Types (UDT) parameters are properties that you can bind the template components to. Since the UDT parameter is a Custom property that encapsulates the UDT tags and some meta properties you can access all this information through a custom property.
To add a component to the template and bind it to parts of UDT
Start with a blank template.
Add components to the template.
Create a Custom property on the template's Root Container, and make the Custom property's Type a User Defined type instead of a Standard data type and click OK.
Select a component on the template, in the component's Property Editor, click the binding icon next to the property that you want to influence.
Select the Property binding and choose the tag from the UDT that you would like the binding to occur and and click OK.