Here's a web site you can use for that purpose:
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You begin by telling it the name and number to be shown on the called party's ID display. Then you continue by telling it the message to be delivered, and the type of voice (male, female, age) to use when delivering the message. The owner of the web site advises you that they _do_ capture your IP address and that threat messages or obscene calls are against the law and are dealt with by authorities.Don't get into trouble!!!
PAT