Some time ago we had a "snowman" contest.
People built and took photos of snowmans they created.
I was the only submitter of a virtual snowman -- an ASCII art picture of a snowman created by DataPower (see snowman.html).
Please find the details, comments, references to documentation in this developerWorks DataPower forum thread:
There you may see how to deal with binaryNode responses of dp:url-open(), regexp:replace()s in action, content-type settings for correct browser display of the result, ...