Create branded stationery in Outlook 2007

Does anyone know how to create corporate branded email stationery in Outlook 2007? I have managed it in other version of Outlook but Outlook 2007 is causing me a problem as it will only let me use MS stationery. I have a .gif and .jpg files to use for the logo and the email background and don’t know how to do this in the 2007 version.

Can anyone help please?

Thanks.