Just call your own number from any phone, and when your voicemail greeting starts to play, press #. It will prompt you for your password, and from that point it's as if you were calling from your phone.
Thank you rcschnoor for helping out jegalpine with the correct information.
jegalpine, I am sorry to learn that you no longer have your device. Were you able to locate it? Have you replaced it? If not, send me a PM with your name and mobile number. I will contact you to review equipment replacement options with you.