Openssl certificate parameters

I run an imap server, which requires me to create a new ssl certificate, every few weeks. Is there any way to set it for a longer life? Or is there a method of passing the parameters to openssl for creating the certificate, so that I don't have to re-enter the info? Currently, I use the command "openssl req -new -x509 -nodes -out imapd.pem -keyout imapd.pem" to generate the certificate, but I still have to manually enter all the info. tnx jk