The most straight forward way is to create a variable to assign the returned value from your query in the Execute SQL task.
I have created variable called SCHOOL_NO and assigned that to Result Set of Execute SQL task. Did you mean that?
I have connected the green arrow from Execute SQL task to Data flow Task. And then in Data Flow tab, I am using OLE DB SOURCE to Data Conversion to Excel Destination.
How to transfer value of Variable SCHOOL_NO to OLE DB Source? or Is there any way I can transfer the value from variable to Excel destination?