Hallo Alexander,
this works for me->
<dtml- with "manage_addProduct['myProduct']">
<dtml- call "NewFolder_add (_.None, _, NoRedir=1)">
</dtml-with>
<dtml-with "_.getitem(idOfNewFolder)">
<dtml- with "manage_addProduct['myProduct']">
<dtml- call "Document_add (_.None, _, NoRedir=1)">
</dtml-with>
</dtml-with>
Bye
Sven