Removing '0' from 3rd place


I want to create a new filed and a logic where the input will be project name which is a combination of letter and and digits. The new input field should replace '0' in the 3rd place of the project. 


E.g- PROJECT NAME: PR120 then new calculation field should remove '0' in the 3rd place

what can be the syntax to remove or not consider 3rd digit if '0'


Ankur Kulkarni