Executing SSIS From Stored Procedure - Need To Get Return Value Into ASP.NET

I'm executing an SSIS package using the following stored procedure

 ALTER PROC [dbo].[SSISRunBuildSCCDW] AS

BEGIN

DECLARE @ServerName VARCHAR(30), @ReturnValue int, @Cmd varchar(1000)

SET @ReturnValue = -1
SET @ServerName = 'myserver'

SET @Cmd = 'DTExec /SER ' + @ServerName + ' ' +
' /SQL ' + 'BuildSCCDW ' --Location of the package stored in the mdb
--' /CONF "\ConfigFilePath.dtsConfig" ' +
--' /SET Package.Variables[ImportUserID].Value; ' +
--' /U "LoginName" /P "password" '

EXECUTE @ReturnValue = master..xp_cmdshell @Cmd, NO_OUTPUT
RETURN @ReturnValue
--SELECT @ReturnValue [Result]

END

 I'm then using a tableadapter to execute this from my ASP.NET page using the following code, Protected Sub ExecutePackage()
Dim ExecuteAdapter As New SCC_DAL.RunSSISTableAdapters.SSISRunBuildSCCDWTableAdapter()
ExecuteAdapter.SetCommandTimeOut(0)
Dim strResult As String
strResult = ExecuteAdapter.Execute()
lblResult.Text = strResult
End Sub

 If I remove 'NO_OUTPUT' from my stored procedure and run it the results contain a field named 'output' with all the steps from my package. Then below this is my return value. In my code I can only return the first step of the package results - which tells me nothing useful. I need to be able to return the return value (0-6) in my code.

When I have 'NO_OUTPUT' in my stored procedure and execute it I am left with just the return value. However no value is returned in my code at all although the package does run. I've tried bother RETURN @ReturnValue and SELECT @ReturnValue to no avail.

Can someone suggest how I can get the value 0-6 to my code?