Contains assertion using Regex failing

Hi,

I'm trying to implement some assertions using regex but I cannot get it working properly

in my soap response I have an element which looks like this:

<UploadResult>BOPS201511001CDIS-7</UploadResult>

All I want to do is locate the element and validate the data inside it.

my regex to match the data is: ((BOPS)+(\d{4})+(\d{2})+(\d{3})+(CDIS)+-+(\d{1,3}))

The issue is I'm not quite sure how to implement this properly. I've tried to use the Contains assertion but it fails. with error missing tolken in response

I'm happy to use the 'Contains' assertion or script assertion.

Any help would be greatly appreciated

Thanks

Ryan