As part of a marketing campaign for sitcom "How I Met Your Mother," CBS will release a single, "Sandcastles in the Sand," for purchase on iTunes, with the video for the song being shown on MySpace.

In one of the show's ongoing plotlines, the character Robin (played by Cobie Smulders) has a dark secret in her past - she was a teen pop star in Canada. The cast of characters on the show discovered her first song, "Let's Go To The Mall," during the first season, and tormented her with the video, which highlighted the striking fashions of the '80s.

In the episode that airs April 21, Robin's equally embarrassing ballad, "Sandcastles in the Sand," comes to light. (Sample lyrics: Together we were going to travel the globe/from Alberta to Ontario) Performed by Smulders, with music and lyrics by Carter Bays and Craig Thomas, the show's executive producers, the song will be available for purchase on iTunes on April 21.

The music video features a Belinda Carlisle-esque Robin as she spins and trips around a beach, makes out with James Van Der Beek and features cameos from Tiffany and Alan Thicke. It will be played on both the "How I Met Your Mother" official MySpace page and the faux MySpace page set up for Robin Sparkles, the character's stage name in Canada.