Williams, 36, will join the band for an album set to be released at Christmas, and then embark on a major stadium tour next summer.
But before everything else, he and Barlow, 39, will do the tongue-in-cheek promo, likening their love-hate relationship to the tormented gay cowboys in the 2005 flick, in their co-written single 'Shame'.
"Everything is in place now to formally announce Robbie's return to Take That for one year only," the Sun quoted an insider as saying.
"He will announce his comeback with a public statement. Then he'll release Shame with Gary," the insider said.
In the video Williams' feelings for the boyband will be depicted.
"In the song there's a line about how he went into Toys R Us and saw the four Take That dolls in a box and realised he felt left out," an insider revealed.
The single is due out in October and will appear on Williams' greatest hits album 'In And Out Of Consciousness'. (ANI)