[Plugin: Contact Form 7] Conditional fields

Is there any way to show a field based on the selection of an option in a dropdown.

For example. I use contact form for a club site.
The form has a field “Regarding” and the options are.

“General Inquiry” “Complaint” “Request” “Booking”

If the user chooses booking, I want to show another required input field called “Fee Requested” so I’ll know how much the band wants to be payed.

Is this to complex for Contact Form 7 or is it possible?