Winfrey filmed her guest role last weekend

Back in April, when Tina Fey was gearing up for the return of "30 Rock" after the writers strike, she had one dream guest star on her mind.

"I still want Oprah to play my best friend," she said then. "I feel like I haven't -- I want to spend time with Oprah, and I don't know what I need to do to make that happen."

Fey must have figured it out, because Winfrey has now made a guest appearance on the show, and NBC has scheduled the episode for Nov. 6. That's one week after the "30 Rock's" season premiere.

Winfrey filmed her long-buzzed-about guest spot over the weekend in New York. Details on just what Winfrey will be doing on the show are scant, though Fey says Oprah "was very funny."

"We are beyond grateful to have her," Fey adds. "Also, I would like to announce that we are officially best friends."

Winfrey joins a list of upcoming "30 Rock" guest stars that also includes Jennifer Aniston, Megan Mullally, the returning Will Arnett and "Gossip Girl" stars Blake Lively and Leighton Meester. The show has earned Emmys for guest stars Elaine Stritch and Tim Conway in the past two years.

"30 Rock" won three Emmys, including Conway's, at last weekend's Creative Arts Emmys and is up for six more at Sunday's Primetime Emmy show.