Excel auto alphabet cell range

This function is useful when you want to export data from matlab to excel.
The cell range should be known, in order to place the data in proper range, if you dont have any prior information of your data range, then the need of auto-calculation of the start and end cell pointers is mandatory.
The input of the function id the number of colums your data contains. the output will be the end cell address in alphabet order, (e.g cell No. 25 will be letter 'Y'), this code is valid up to 18278 colums.