The Piano Man hasn't shed his Average Joel persona as a rehab patient at Connecticut's elite Silver Hill Hospital — he's opted to share a 10-bedroom house with other patients rather than stay in a celebrity cottage.

But sources said Joel — who's at the sprawling psychiatric and substance-abuse center to do battle with his addictions — has been getting some special treatment. 

He hasn't been eating lunch with fellow patients in the hospital's main dining room because of all the cameramen camped outside who have their telephoto lenses trained on it. And then there's the police car that's been patrolling the perimeter of the bucolic, 60-acre campus 24/7 ever since the 53-year-old rocker arrived. 

"Last Friday, the hospital contacted us requesting extra security," said New Canaan police spokesman Sgt. David Ferris Jr. 

"They just said they had a VIP there," he said, explaining that under the hospital's confidentiality policy, even the local cops aren't told the identity of the rich and famous who check into Silver Hill to kick their addictions. 

"We've had an officer there around the clock ever since," Ferris said. "We're at the main gate, we're driving around up and down Valley Road, and we're in touch via radio with Silver Hill security. 

"We'll be there until they tell us we're no longer needed." he said. 

Although the hospital doesn't acknowledge that Joel is a patient, his Columbia Records publicist on Wednesday said Billy had checked into the facility "for a planned, 10-day stay to deal with a specific and personal problem that had recently developed." 

She would not elaborate.

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