>>>How to calculate the weeks .
>>>Example 34/99 to 23/00....
>>>If anyone has done this type of calculation and is willing to share with me the solution, I would greatly appreciate it.
>>
>>What's wrong with
>>
>>(Date2 - Date1) / 7
>Its format week/year....
Convert your WWYY format into a date format and use Marks calculation:

(({01/01/2000} + ( 23 * 7)) - ({01/01/1999} + (34*7)))/ 7 rounded down should give you the number of weeks.

Use the date that is the first day of the first week to be more acuarate as opposed to the 1/1

HTH