My thoughts are: The judge used the old case to decide that the same issues you want to litigate now have already been llitigated and decided in the older case. That is called "res adjudicata" meaning the thing has already been litigated. If that is what the judge was doing then I don't see a problem; but you can always appeal whatever you don't like, right?
Then simply ask for the judge (or the judge's clerk) to give you the reference - this should be easy to find if it was referred to and relied upon by the judge.
If you can't get in informally, then file a formal motion requesting the judge to identify the other case for you.
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