How to convert week numbers(1-53) to 1,2,3,4 for every month

Dear BO Gurus,

I am facing very critical issue in my current project, we have a requirement to show months and week but as per calculations in bex it is displaying weeks like 1..52 but our requirement is need to show 1.2.3.4.5how many weeks that month having and again for second month also it should show 1,2,3,4.

Is it possible in webi please adivse me.