I have a cell refering to another workbook. example: April.xls
I want to change all cells with that refrence but without changing each one
individually, so i created a cell which i input the current month. How do i
link it to all other cells so instead of getting information from april.xls
it will get information from july.xls

examle formula:
=[April.xls]Sierra'!H7

how do i enter in this formula the cell no. instead of april?