Multiple answering messages?

I get a LOT of telemarketers as I have my business line forwarded to my cell. I would like to record the sound of a FAX machine to play when I get a telemarketer call but I need to have my business message for when customers call and I don't have time to answer. Is there a way to do this or do I have to just record the FAX "noise" on a handheld recorder and play it when a telemarketer calls? I do have an old ZOOM H2 that should work well for this but it would be easier if I could set up a second answering message that I can manually choose when I need it.
My reasoning is that these people will remove my number if they keep getting what they think is a FAX machine.

Any ideas? Any APPS that might help me? I think I saw that there are actually some APPS that you can use to block selected area codes. I am fairly new to smart phones, I used to have an ignorant phone, a Blackberry Pearl, with the trackball surround held in place by clear tape... but I digress, lol.

Thanks,
Julien