When you are successful in a high level you think you are in heaven. I've found there is an expression which is "touching the sky" in this sense of being gloriously happy, as among gods. But I have a doubt whith this "the".
I've never heard of this idiom. I've heard of 'on cloud nine' to mean the same but wouldn't use it except in informal speech since it's a cliche.
There are many other idioms that mean extremely happy, eg 'as happy as a lark', 'over the moon', but I'd take care using them in a piece of writing as many are cliches.
Hope this helps