Google Sheets Formulas

gistfile1.txt

// REMOVE BEGINNING OF N CHARACTERS OF TEXT

  // (Removes first three characters of strings located in array)

      =ArrayFormula(right(D1:D15,len(D1:D15)-3))
  
  // (Removes the first character in first column and the first three columns in the second column)    
      
      =ArrayFormula(replace(A1:B10,1,3,""))
      
  // Remove text before 1st appearance of character "_" in this example.      
        
      =if(ISTEXT(TRIM(LEFT(B1,FIND("_",B1) - 1))),TRIM(LEFT(B1,FIND("_",B1) - 1)),B1)

// INDEX MATCH

  //  Finds matching text in column and displays cell content adjacent to cells with unique string matches
      
      =index('Other Spreadsheet'!A:A,match(A1,'Other Spreadsheet'!B:B,0))