How about \<0+ and replace with nothing?
cool. that worked fine.
Or, for whatever reason you want to retain the contents, but want to change the visual appearance of the leading zeros to "invisible", use the GREP by Peter and apply it as a GREP style to your paragraph style setting a character style with fill and stroke color to "[None]".
> cool. that worked fine.
It also removes any sequence of zero's in its entirety. If that could be a problem, make sure there is always one digit left: