formula to combine Primary and all Secondary locations into one field?

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I am not a reporting guru...so I'm hoping somebody can help me out with this!

We often post requisitions for more than one location.  When we want to pull all of the locations into an XIR3 report, we end up with multiple rows per requisition, if there's more than one Secondary location.  First row give Primary location plus first Secondary location.  Second row gives Primary location plus second Secondary.  Third row gives Primary location plus third Secondary.  And so on.  This is problematic, because the same one requisition gets counted several times in our stats.

I'm sure there must be a way to create a formula that will combine all the locations together in one field, separated by semi-colons or something.