I have managed a workaround, it is a bit longwinded but it seems to work as I have covered every scenario I think.

USE [TestData]

GO

/****** Object: StoredProcedure [dbo].[droptable] Script Date: 07/10/2013 14:11:37 ******/

SET ANSI_NULLS ON

GO

Alter procedure [dbo].[checkcolumnsexists]

AS

BEGIN

/* They all exist so exec the full cleanse procedures */

if dbo.ColumnExists('SOFTWARE_MANUFACTURER') = 'Y'

and dbo.ColumnExists('PRODUCT_NAME') = 'Y'

and dbo.ColumnExists('PRODUCT_VERSION') = 'Y'

BEGIN

Exec cleanseDATA;

END

else if

/* If the software manufacturer and product name exists so exec both procedures */

dbo.ColumnExists('SOFTWARE_MANUFACTURER') = 'Y'

and dbo.ColumnExists('PRODUCT_NAME') = 'Y'

BEGIN

-- exec softwaremancleanse;

-- exec productnamecleanse;

END

else if

/* If the software manufacturer and product version exists so exec both procedures */

dbo.ColumnExists('SOFTWARE_MANUFACTURER') = 'Y'

and dbo.ColumnExists('PRODUCT_VERSION') = 'Y'

BEGIN

-- exec softwaremancleanse;

-- exec productversioncleanse;

END

else if

/* If the product name and version exists so exec both procedures */

dbo.ColumnExists('PRODUCT_NAME') = 'Y'

and dbo.ColumnExists('PRODUCT_VERSION') = 'Y'

BEGIN

-- exec productnamecleanse;

-- exec productversioncleanse;

END

else if

/* Only the software manufacturer exists so execute cleanse Software manufacturer procedure */

dbo.ColumnExists('SOFTWARE_MANUFACTURER') = 'Y'

and dbo.ColumnExists('PRODUCT_NAME') = 'N'

and dbo.ColumnExists('PRODUCT_VERSION') = 'N'

BEGIN

-- exec softwaremancleanse;

END

else if

/* Only the product name exists so execute cleanse product name procedure */

dbo.ColumnExists('SOFTWARE_MANUFACTURER') = 'N'

and dbo.ColumnExists('PRODUCT_NAME') = 'Y'

and dbo.ColumnExists('PRODUCT_VERSION') = 'N'

BEGIN

-- exec productnamecleanse;

END

else if

/* Only the product version exists so execute cleanse version procedure */

dbo.ColumnExists('SOFTWARE_MANUFACTURER') = 'N'

and dbo.ColumnExists('PRODUCT_NAME') = 'N'

and dbo.ColumnExists('PRODUCT_VERSION') = 'Y'

BEGIN

-- exec productversioncleanse;

END

END