I am calling rest uri from jQuery ajax with filter string comparison startswith as below

/_api/lists/getbytitle('Stations')/items?$select=Id,City_Code,City_Name_EN&$filter=startswith(City_Name_EN,'M') and Active eq 1&$orderby=City_Name_EN asc

Which is working very good. And I am displaying text by programmatically as below

Mumbai(Mum) i.e. City_Name_EN (City_Code)

but is there anyway to filter startwith(City_Name_EN (City_Code),'M') .

I tried to make calculated field in above format. But rest api does not allow to filter calculated field.

Is there any way to filter like that.