total sales on customer profile

[purple-heart]

I have had a look at the customers.php page under admin and would like some advice as to how i should go about adding one field in on the customers page for total_sales (it could replace the GV balance as my store wont offer this service anyway and isnt really needed at this early stage.

Then on the edit customer page how I would best add the total_sales from phporders table on this page? (if the customer has more than one purchase it will need to add this up so it is a true total sales). It can be view only as it doesn't need to be edited.

Pretty much need to add the report customer orders total into the customers page so I can see totals to easily apply discounts based on the total sales.

I hope someone could help point me in the right direction.