Hi @Othboury ,
Try,
<input choiceButton="true" createMode="none" form="nms:recipient" fullLoad="true" img="nms:recipient.png" label="Recipient" newFromModelOnChange="true" noZoom="false" schema="nms:recipient" selectionPath="/tmp/model" type="linkEdit" xpath="/tmp/@model"/>
Or,
In your schema, create a link between your custom schema and recipient schema, and give name as name="recipient" in element tag.
Go to input form, and add the below script,
<input colspan="2" createMode="none" noZoom="false" xpath="recipient"/>