Sales order item quantity validation as per customer group

Hi all,
I am trying with a scenario where i have to restrict items daily quantity as per customer group.

I customize a table in customer group where i link item and a field item limit and i make a custom field in the item master itself with the name item limit.

In customer group Item limit table item limit pulls from the item master.

Now i want to validate those customers present in that particular while making sales order that while making sales order against those customers having those items limit it should validate the item limit quantity on that particular date.
also i am pulling the same item limit in sales order item table from the item master.

How i can make it possible .please help me with your suggestions so i could get help while solving that issue.
Thanks in advance.