SQL - How to SUM and use WHERE clause on this SUM using 4 tables?

I need to build a tool which sorts my customers on several parameters and then exports it to CSV. Everything's working fine except my SQL query (I've always been bad at it).

Here is my DB structure:

Customers (id, CustomerLogin, CustomerNom, CustomerPrenom, CustomerReference)
Orders (OrderId, OrderTotal)
Products (ProductId, category)
OrderProduct (CPId, OrderId, ProductId)

I need to sort my customers to build a mailing list (CustomerLogin is a mail address). Filters I need to implement:

Orders number
Orders total
Product Category

Here's my current query(using some PHP variables for total and categories):

SELECT C.id, C.CustomerReference, C.CustomerNom, C.CustomerPrenom, C.CustomerLogin, O.OrderTotal, O.OrderId  
FROM customers C  
    JOIN orders O  
    ON C.id = O.CustomerId  
    JOIN OrderProduct OP  
    ON O.OrderId = OP.OrderId  
    JOIN products P  
    ON OP.ProduitId = P.ProduitId  
WHERE O.OrderTotal >= $total  
    AND P.category IN($product_categories);

So this returns me data for every customer entry in the order table where these orders are filtered by total and product category. For example:

C.Id, C.ref, C.nom, C.prenom, C.login, O.OrderTotal, O.Id  
1 - REF1 - DOE - John - [email protected] - 550 - 1  
1 - REF1 - DOE - John - [email protected] - 150 - 4  
1 - REF1 - DOE - John - [email protected] - 800 - 8  
5 - REF5 - BOND - James - [email protected] - 007 - 25  
8 - REF8 - ANOTHER - Dude - [email protected] - 50 - 12

What I'd like to get:

C.Id, C.ref, C.nom, C.prenom, C.login, OrdersTotal, OrderNumber  
1 - REF1 - DOE - John - [email protected] - 1500 - 3  
5 - REF5 - BOND - James - [email protected] - 007 - 1  
8 - REF8 - ANOTHER - Dude - [email protected] - 50 - 1

Problem is I also need to filter OrdersTotal and OrderNumber, so how can I sum and display it in my "SELECT" and then filter it in the "WHERE"? Is that even possible? I thought about using subqueries or other stuff but I'm pretty bad at it so I could use some help on this.

Sorry for that long question but I need to be precise on this! Hope you guys will understand what I mean and be able to help me, thanks!

p.s.: I've translated my table and column names so you can understand, there might be some errors but it's working on my side.

UPDATE
Thanks to Surajit Biswas this is the solution:

SELECT * FROM(    
    SELECT C.id, C.CustomerReference, C.CustomerNom, C.CustomerPrenom, C.CustomerLogin, SUM(O.OrderTotal) order_total, COUNT(O.CustomerId) nb_com  
    FROM customers C  
        JOIN orders O ON C.id = O.CustomerId  
        JOIN OrderProduct OP ON O.OrderId = OP.OrderId  
        JOIN products P ON OP.ProduitId = P.ProduitId  
    WHERE P.category IN($product_categories)  
    GROUP BY C.id, C.CustomerReference, C.CustomerNom, C.CustomerPrenom, C.CustomerLogin
    )A 
WHERE A.order_total >= $total AND A.nb_com >= $nbcom

Everything's working fine!
All credits @Surajit Biswas.

Solution

I would have used something kind of this:

SELECT OrderID, sum(Quantity) as sumquantity
FROM OrderDetails
group by OrderID

When my table structure is like:

OrderDetailID   OrderID ProductID   Quantity
1   10248   11  12
2   10248   42  10
3   10248   72  5
4   10249   14  9
5   10249   51  40
6   10250   41  10
7   10250   51  35

It gives me the output as:

ord_id  sumquantity
10248   27
10249   49
10250   60
10251   41

In fact at your case also it is easy...

SELECT C.id, C.CustomerReference, C.CustomerNom, C.CustomerPrenom, C.CustomerLogin,
      SUM(O.OrderTotal) order_total
FROM customers C  
  JOIN orders O  ON C.id = O.CustomerId  
  JOIN OrderProduct OP ON O.OrderId = OP.OrderId  
  JOIN products P ON OP.ProduitId = P.ProduitId
WHERE O.OrderTotal >= $total  
  AND P.category IN($product_categories)
GROUP BY C.id, C.CustomerReference, C.CustomerNom, C.CustomerPrenom, C.CustomerLogin