Not sure how you can block requesters from a specific program, but there is a utility that blocks all system requesters.
I forget the name of it, but it was often used when running a Telnet server. Using Telnet, you only have CLI access, so if you did something which caused a requester to pop up, you'd have no way of seeing or canceling it.
Look on Aminet.
Otherwise, try assigning Lala: to RAM: (if it's only looking for the one volume) which should also stop it.
