Crystal Reports - Customer Statements with Ageing

Hi,

I have created a custom accounts receivable statement in Crystal reports 2011.

However, I am currently facing some challenges:

1. How can I put a specific date so that the statement will show data upto that date e.g. today is 22/05/2014, but I want to run a statement as 30/04/2014 - how do i achieve this?

2. How can I insert formulas into crystal report that will allow me to calculate the ageing on the above as at date?

Any help would be highly appreciated.