In the jQuery onHandler extension, select "JS Code" from the drop down when setting your data source, and do something like this:
To explain each part of the expression in detail:
This bit is a regular expression that will match the SKU value:
... but we want only the captured SKU, so we need to address the second part of the match array (index 1), hence:
(/(?:sku\=)(.*)(?:&)/) //  will return the 2nd match from the regex
...will return the URL of the item you clicked on, which I'm assuming is where the string you posted originally came from.
I hope this helps - it's a bit tricky to explain without getting too verbose. Let me know if you have any questions!
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