This document introduces a block-based data fusion language for defining complex event processing queries in smart cities without requiring expertise in CEP languages. It uses processing blocks that can be chained together to represent queries. Templates define custom blocks with free input/output parameters. Wildcard template binding selects data streams at deployment time based on stream metadata or SPARQL constraints. This enables non-experts like city administrators to define CEP queries for large volumes of sensor data in smart cities. Future work includes implementing full SPARQL-based wildcard instantiation and usability testing.