If you have a friend who is 'in' on the whole LOA thing, you could get them to call you and do a roleplay where you pretend they're the person you want to call you.
Then you could tape the roleplay and use it every day to pretend you got the call.
You could also set up an email account in that person's name and email your main account so you get used to having messages in your inbox...maybe with subjects that you want them to talk about with you, so your inbox would look like:
Email From: Joe Bloggs --- Subject: I've been thinking about you
Email From: Joe Bloggs --- Subject: Want to meet up this weekend?
Email From: Joe Bloggs --- Subject: When do you finish work? I want to call you!
Email From: Joe Bloggs --- Subject: You're amazing!
And then get your friend who is on on LOA to send you text messages from their phone with those kinds of messages but change their name in your address book to Joe Bloggs or whatever this person's name is.
And then make postcards from Joe Bloggs from all over the world and stick them up all over your wall!
And then make a message pad and stick it next to your phone and write messages as if someone had taken message for you while you were out, like:
2:15pm - Joe Bloggs called
2:30pm - Joe Bloggs called again, I told him you were still out
3:00pm - Joe Bloggs called again, says he misses you
3:03pm - Joe Bloggs called again, he said he accidentally pressed 'redial' but I think he just REALLY want to talk with you!
5:00pm - Joe Bloggs again. Wants to take you out for dinner tonight. Please call him back ASAP..
5:01pm - JB says he'll pay for dinner.
5:15pm - Joe Bloggs wants to know if you like Italian or Seafood?
5:41pm - You Know Who called AGAIN - he's sick of waiting for you to call back so he's just going to turn up here wearing a tux and carrying a bunch of flowers. He said he's taking you out whether you like it or not. He'll bring his limo.
Make sure Joe Bloggs doesn't actually see your phone / email / message pad before you delete them all though!