Yeah ,,, i got it .
Instead of trying to rename ... @tweets = just exclude them from the feed using ypipes.
Fetch feed then filter.... choose item.description - at the top menu choose items that contain "any" then in the "item.description" box enter @ . save feed .
And your done .... now nobody knows you are retweeting someone;s timeline.
If you want to take it a little further - incorporate "babelfish to translate into spanish then back to english before you retweet"
Booyakah _