Before speaking with the other insurer, you should contact your insurance company and let them know about the court date and that you've been contacted by the other person's insurer. Your insurance company might appoint a lawyer for you; they might call the other insurance company directly; or they might otherwise give you instructions on how to handle it. Another thing to check-- are you sure it's not an attorney representing the other guy's insurance company (as opposed to a claims person) who's calling you?
make sure you provide everything to your insurance company immediately! your insurance company should provide an attorney to defend you.
Read more about dealing with insurance companies at:
Good Luck to you,
/ Thomas James