Conditional field query on headline value

Hi,
is there a possibility to to query fields in a blueprint based on the headline field?
I tried it but it doesn’t work well I tried also the plugin whenQuery. So if someone knows a solution I would apreacheate if he/she is writing a answer!

I need only for one specific page an adittional field in a structurefield and i don’t want to create a complete own template for this.

Best