PHPExcel如何使用setformula a1()将表列链接到单元格

I am using a PHPExcel for xls creation. how can i link a sheet column to a drop down cell. i have created a drop down in xls but how can i get sheet column like whole A column in drop down for drop down values. In excel i have done this manually when i link a sheet column to any cell its making formula like this for xls creation. how can