update table fieds based on trigger inserted

[mapsv3]

In a project, user will key in data in a software and data will be export into SQL Server 2008 R2

Once SQL Server identify there is an inserted data (new row), it will trigger code to update table Abbyy base on business rule.

In table Abbyy, its contain column

[DocID] [varchar](20) NOT NULL,
[FormNo] [varchar](20) NULL,
[DateOfReceive] [varchar](10) NULL,
[ActualSubmit] [int] NULL,
[ServiceType] [varchar](10) NULL,
[ProcessingDate] [date] NULL,
[CustName] [varchar](50) NULL,
[CustPhoneNo] [varchar](12) NULL,
[EngineNo] [varchar](15) NULL,
[VehRegNo] [varchar](10) NULL,
[Mileage] [int] NULL,
[DateOfService] [date] NULL,
[DealerCode] [char](10) NULL,
[CouponStatus] [varchar](10) NULL, **(only accept 'Approve' OR 'Reject')**
[RejectCode] [varchar](10) NULL,   **(only accept null, 'A1', 'A2', 'A3', 'A4', & 'A5')**

My business rule requirement is

A1 Engine No doest not exist in ABC System
A2 Registration No does not exist in ABC System
A3 Engine No and Registration No does not matched with each other
A4 Engine No has been repeated more than twice
A5 Date of Service More than Processing Date 7 months


EngineNo must exist in database.

For previous records, EngineNo with CouponStatus='Approve' is count and should ignore CouponStatus='Reject'.

If EngineNo with CouponStatus='Approve' repeated more than twice then Update Table Abbyy CouponStatus = 'Reject', RejectCode = 'A4'

How should I code in trigger for business rule A4 so it only check CouponStatus='Approve' and ignore CouponStatus='Reject'.

Here is my trigger code

USE [master]
GO

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO


ALTER TRIGGER [dbo].[BusinessRule]
ON [dbo].[Abbyy]
AFTER INSERT
AS
BEGIN

SET NOCOUNT ON;


DECLARE @Identity varchar(225);
DECLARE @RegNo varchar(225);
DECLARE @ProDate date;
DECLARE @SerDate date;
DECLARE @PriKey varchar(255);
DECLARE @CouStatus varchar(255);

SELECT @Identity=EngineNo, @RegNo=VehRegNo, @ProDate=ProcessingDate, @SerDate=DateOfService, @PriKey=DocID, @CouStatus=CouponStatus FROM Inserted


IF EXISTS (Select EngineNo
            From Abbyy
            Where
                NOT EXISTS
                (Select EngineNo
                 From eDaftarOwnerDetail
                 where eDaftarOwnerDetail.EngineNo = @Identity))

    UPDATE Abbyy
    SET CouponStatus = 'Reject', RejectCode = 'A1'
    WHERE EngineNo = @Identity
    and DocID=@PriKey

Else If EXISTS (Select VehRegNo
                From Abbyy
                Where
                    NOT EXISTS
                    (Select VehRegNo
                     From eDaftarOwnerDetail
                     Where eDaftarOwnerDetail.VehRegNo = @RegNo))
    UPDATE Abbyy
    SET CouponStatus = 'Reject', RejectCode = 'A2'
    WHERE VehRegNo = @RegNo
    and DocID=@PriKey

Else If EXISTS (Select EngineNo, VehRegNo
                From Abbyy
                Where
                    NOT EXISTS
                    (Select EngineNo, VehRegNo
                     From eDaftarOwnerDetail
                     Where eDaftarOwnerDetail.EngineNo = @Identity
                     and eDaftarOwnerDetail.VehRegNo = @RegNo))
    UPDATE Abbyy
    SET CouponStatus = 'Reject', RejectCode = 'A3'
    WHERE EngineNo = @Identity
    and VehRegNo = @RegNo
    and DocID=@PriKey

Else If EXISTS (Select COUNT(1)
                From Abbyy
                Where EngineNo = @Identity                          
                Group by EngineNo 
                Having COUNT(1)>2)
    UPDATE Abbyy
    SET CouponStatus = 'Reject', RejectCode = 'A4'
    WHERE EngineNo = @Identity
    and DocID=@PriKey
    and CouponStatus=@CouStatus

Else If EXISTS (Select ProcessingDate, DateOfService
                From Abbyy
                Where
                datediff(day, @SerDate, @ProDate)>210)
    UPDATE Abbyy
    SET CouponStatus = 'Reject', RejectCode = 'A5'
    WHERE CONVERT(DATE,ProcessingDate,102) = CONVERT(DATE,@ProDate,102)
    and CONVERT(DATE,DateOfService,102) = CONVERT(DATE,@SerDate,102)
    and DocID=@PriKey

Else
UPDATE Abbyy
Set CouponStatus = 'Approve', RejectCode = ''
WHERE EngineNo = @Identity

END

[mapsv3]

any one can help on this. thank you