Harry's Law star Bates will play the spirit of the late Charlie Harper - the character originally portrayed by Charlie Sheen.
"We knew we wanted Charlie's spirit to visit... Alan (Jon Cryer)," Lorre told TV Guide. "When Kathy's name was first floated as 'his incarnation' we all just started laughing and decided to reach out to her.
"We were also determined to stay true to the character of Charlie Harper, and that was a promise I made to Kathy when we first talked. Thankfully, Kathy immediately saw the twisted humour of it all and signed on."
Lorre claimed that Bates's eventual performance helped make the show's April 30 instalment "one of the best episodes of the series".
"It's pretty damn funny watching this world-class actress beautifully recreate not just Charlie's character, but also the sibling relationship he had with Jon Cryer's character, Alan Harper," said the exec.
"I'm hoping we can have her back in a recurring role - Alan's demonic spirit guide. She really rocked this thing."
Two and a Half Men airs on Mondays at 9/8c on CBS.
> Two and a Half Men: Renewal expected, Ashton Kutcher on board?
Watch a promo for Two and a Half Men below: