Hi Mieke,
You could test __counter_value_from_server__ in your Template command and assign labels accordingly: Template( row => newTrial( __counter_value_from_server__%2?"secondblock":"firstblock" , /* ... */ ) )
Note: __counter_value_from_server__ is only defined after your script has been evaluated, so you cannot use it outside Template (whose execution is delayed to fetch the tables)
Jeremy