Many people use the CELL worksheet function to return the name of the current Excel workbook. A common way to use the function is as follows:
Using the CELL function in this manner is fine, provided you only have one workbook open at a time. If you open more than one, then this usage can cause problems. Why? Because when used this way, CELL returns the name of the currently active workbook, not the workbook in which the formula is used.
To always return the name of the workbook in which CELL is used (sometimes called the “parent workbook”), you must alter the formula just a bit:
By adding a cell reference as the second parameter in the function, you are telling Excel that you want the name of the file containing that cell reference. In other words, CELL will return the name of the file in which cell A1 of the current worksheet is located. (You can also provide any other cell reference in place of A1, if more appropriate.)