How to find the position of a characted in a string

Hi,

I am trying to find the position of a character in a string which appears
multiple times.

The POSITION function returns the position of the character when it first
occurs.

For eg:

select position ( ' ' in 'Hi How are you');

This returns the result as "3".

But i need to result to be

3
7
11

Can anyone please let me know what would be the best way to do this.

Thanks