When SelectQuery returns zero records call a business process

Hi,

We have a environment where Creatio is System of engagement and core processing is done by backend system. When we query in the Creatio (say using Search field) Creatio invokes SelectQuery -- so how can trap the row count it returns and call a business process if it is zero -- the business process will invoke a API which gets the data from backend application and updates creatio 

Just business process with ability to inovke API and load Creatio objects is ready and working fine just how to invoke from Search (from Freedom UI)

Thanks and Regards