Jon Boy UK Wales

My mk1 galaxy 2.3 ghia x automatic has an issue and hopefully someone could help out with the possibility of pointing me in the right direction. Basically the car when it's in 'D' appears to be slipping. The car start and drives off ok. It feels like it's slipping 'being lazy' going into gear. You can feel the car changing gear and then over revs before going into gear. I either press a little harder on the accelerator and it goes in. Or ease off and press the accelerator again and it goes in. The box seems ok if I select 1st 2nd or 3rd and Reverse. Only havens when in Drive. Any ideas please? I have read a few posts with similar scenarios but I guess everyone had slightly different variations.