Voicemail

I will be out of the country for a while and I don't plan on turning on the roaming. I want to record a message that would play anytime someone calls me in which I would direct the caller to text me to the alternative phone number, without giving the caller an option to leave a voicemail. So the phone would ring, the message would play, the call would end. Can I do this and if so, how can I do it?

Thanks in advance!