03/11/2008 at 12:00 AM EDT
Neil Patrick Harris
is embracing the news
that Britney Spears
will appear on his CBS sitcom How I Met Your Mother
-- and he's also having some fun with the idea.
"I was shocked that Madame Spears was willing to come and do some acting," Harris, 34, tells Entertainment Tonight
. (See the video here.
Noting "she hasn't acted in a while," Harris goes on to say, "This is a very interesting role. It is very not like her at all in real life in any of her previous chapters."
In April 2006, Spears guest-starred on NBC's Will & Grace
as a two-faced conservative talk-show host alongside Sean Hayes's flamboyant character Jack.
On How I Met Your Mother
-- set to air March 24 -- "She plays the secretary to another girl that Ted Josh Radnor
is after. So, it will be very unlike any Britney we have seen before, and we have seen a lot of Britney recently."
Harris also tells ET
that paparazzi will not be a problem when Spears, 26, shows up, because the series is shot on the secure FOX lot.
But he jokingly muses: "What if she shows up on set and she is absolutely, totally normal and that whole thing has been a big ruse?"
As he imagines it, "She is smoking a cigarette and says, 'Oh yes, it is all a big bit. I have a master plan.' " --Stephen M. Silverman