How do I get the error template to show up on the right side of the control?

I'm implementing an error template for validation, in VS 2012. This page on Validation.ErrorTemplate Attached Property is quite helpful. However, when using it I've found that it will put the "!" to the left of the textbox that has invalid data in it. How do I move the "!" to the right of the textbox with invalid data?

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Rod