Comedy Central

Lisa tells us, "I am personally thrilled to death that they chose Charlie and I'm glad he's desperate enough to have accepted the challenge. I mean, come on -- the guy was replaced by Ashton Kutcher. I guess he now knows how Bruce Willis felt!"

But she adds, "Sadly, I'm actually booked to do a show that night already, but if there's any way I can get out of it, all I can say is, "Charlie, here I come!'"

The show is scheduled to tape September 10 in L.A.

Sheen released a statement saying, "You could say I've been providing kindling for this Roast for a while ... It's time to light it up.& It's going to be epic."

The Roast will be taped in Los Angeles on September 10 ... and it will air on Comedy Central on September 19 -- which is, not coincidentally, the same night the revamped "Two and a Half Men" is set to premiere.

A rep for Comedy Central says, "Charlie has assured us that nothing will be off limits in this Roast which scares even us."

Story developing ...

During a burger run in L.A. last night, Martling told us that Howard loves radio so much, he'll be doing it "until the day that he dies."

Both Greg Giraldo and Joan herself made the jokes -- but they leave us with just one question ...

There's a reason insult master Lisa Lampanelli didn't show up to the Comedy Central roast of Joan Rivers this weekend -- if she couldn't be in charge, it wasn't worth her precious time.

A week after Kathy Griffin was announced as the roastmaster for the event in Los Angeles, Lampanelli -- who's usually the headliner at these things -- dropped the following message on her Twitter page:

"No Joan Rivers roast for me this year. Not worth doing if I ain't roastmaster -- besides summer is for fun, not work."

Perry Caravello, the one-time "star" of a practical joke flick, filed suit today in Los Angeles County Superior Court claiming, among other things, the three funnymen owe him $10.5 million.

For several years, Caravello was duped into believing he was going to play the lead role in the faux action flick "Windy City Heat." Every actor and member of the crew was in on the joke -- except Caravello. The final product, er, joke, aired in 2003 on Comedy Central.

In his suit, Caravello claims the defendants "falsely and fraudulently" represented the project, and promised him, among other things, that he "would be paid 10 million dollars if he placed his penis in a mousetrap." Caravello says he "was severely injured when the trap literally went on his manhood." Ouch. To add insult to injury, Caravello says he's suffered "humiliation and emotional trauma" because the video has circulated the Internet. Talk about viral.

Caravello is suing for the $10.5 million that he says he is owed, plus damages and medical expenses.