Shams,
If while creating contract sales order customer ABC is used.
and while creating normal sales order customer 123 is used.
Then by maintaining the correct condition records for the pricing condition types (ZCAN, ZNOR) would give you the solution.
For ZCAN, ZNOR, the condition table would have field "Customer number"
In VK11, for ZCAN maintain one field as customer = ABC
and for ZNOR maintain one field as customer = 123
Thus went creating a sales order with contract customer ABC, ZCAN would populate.
Thus went creating a sales order with contract customer 123, ZNOR would populate.