Assuming the computed URL is valid, that would work with a web viewer rather than a calculation field of type container. I could be wrong, but I don't think a container field can use a file reference that includes a URL like this.
Try using this expression with a web viewer and see if you can get it to work. You can look this up in FileMaker help to work out the exact nuts and bolts for doing this.
Thank you this works well.... now that I figured out how to remove the hidden carriage return in the webviewer by using the subsitute (Text) command
Very frustrating when you are a newbie!!!!