dynamic custom properties from external data

Hi,

I would like to create a blueprint with a dynamic dropdownlist based on an external data (vco workflwlow , database, or other).

I think it's not possible, but can I, at least, create a vco workflow associated to an advanced service which could update the values of a property attribute ?

I didn't find this with the vcac plugin in vco.

Thanks for your help

Vcac version : 6.1

external vco version : 5.5.2.1