It's about a horse that 2 children try to hide because their father wants to use/sell the horse. The horse has a white star on its forehead and they use boot polish to cover up the horse and therefore stop if from being identified. I think the children may even hide the horse in some kind of cave and then ride it in a rodeo.

I think the film is portrayed as being set in the Wild west maybe Montana, Wyoming or Arizona.

Many thanks in anticipation for any title suggestions

Juniper

"Into the West" (1992) ?

Thank you for your reply but I'm sorry to say that this is not the film I was thinking about.