I would like to apologize for any misunderstanding that might have appeared in our discussion and thank you for being patient and explaining what exactly your use case is.
From the shared details on your end I can say the scenario is much clearer to me now. Given this, the direct answer to your questions is yes, you can reference multiple data columns in a find expression using both Coded Step
and Standalone Code File
To assist you further with this, I have created a sample test scenario for with detailed comments in it, explaining how the above mentioned can be achieved. In few words, what I did is to create a standalone code file in your project which consists of two methods – one that defines the find expression and another that finds the element. Once you create this code file you will be able to use it in any other test in your project. In addition to this I have created a coded step in the test itself which calls the first predefined method from the Code Item and uses the element with the actual data from `Local data` tab (it is located in the WebTest).
Please, refer to the attached project and keep in mind that this test cannot be executed and it is only an example on how to achieve the desired functionality. You should modify it accordingly to work properly for your project.
Let me know if you have further questions.