'What does the expression : Select `(column1|column2|column3)?+.+` from Table in SQL means?

I am trying to convert a SQL Code into Pyspark SQL. While selecting the columns from a table , the Select Statement has something as below :

Select a.`(column1|column2|column3)?+.+`,trim(column c)  from Table a;

I would like to understand what

a.`(column1|column2|column3)?+.+`

expression resolves to and what it actually implies? How to address this while converting the sql into pyspark?

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