Howto call a model-extension gtl-template from within trigger template?

Hi,

within a Trigger template or Trigger item template PD will find ( and execute ) templates which are located within several categories of dbms-extensions. But how can I call a template which is placed within model-Extension?

My template "Test" resides in xem-file "HuPExtV2" as follows: Profile\Shared\Templates\Helper\Test. Tracing will Show the exact Location as :

HupExtV2::Profile\Shared\Templates\Helper\Test.

Calling "Test" works from a "Generated Files" entry within Xem-Extension,  but does not work from a Trigger-Template.

I tried: "%HuPExtV2::Profile\Shared\Templates\Helper\Test%" but seems to be wrong Syntax.

Any help is appreciated

Regards

Wilko