How do I create a sub element in a custom resource schema in ACS?

[robayzma]

I would like to create an element with several attributes in the profile extension schema so something like the postalAddress structure in the standard profile schema nms:recipient

   <element category="1120_location" name="postalAddress" template="nms:common:postalAddress">

      <attribute expr="SubString(JuxtWords3(Smart([../@salutation]), Smart([../@firstName]), Upper([../@lastName])), 1, 38)" name="line1" />

      <attribute expr="Upper(SubString([../location/@address1], 1,38))" name="line2" />

      <attribute expr="Upper(SubString([../location/@address2], 1,38))" name="line3" />

      <attribute expr="Upper(SubString([../location/@address3],        1,38))" name="line4" />

      <attribute expr="Upper(SubString([../location/@address4],       1,38))" name="line5" />

      <attribute expr="SubString(JuxtWords([../location/@zipCode], Upper([../location/@city])), 1,38)" name="line6" />

      <attribute _operation="delete" name="line7" />

      <element expr="@line1+'\n'+@line2+'\n'+@line3+'\n'+@line4+'\n'+@line5+'\n'+@line6" name="serialized" />

    </element>

How do  I do that? It seems I am only able to create attributes in the designer

Kind regards

Robert