Hey Kevin,
Thank you for writing into the forums!
Please do just pay attention to the developer.twitter.com site, as support.gnip.com is no longer supported and will be removed soon.
Which product are you using? If you are using the Premium or Enterprise versions of the Search API or PowerTrack API, you should be able to use the retweets_of:kevinhoang operator.
It is a little more challenging to do this for tweet IDs. I recommend that you use the phrase operator ("string of words") for a good portion of the Tweet’s text and then use the is:retweet operator (not available with Sandbox).
Please let me know if this does the trick for you.