Create dropdown filter options for a column when you create a .csv file from php

Does anybody know how to create drop down/ filter options for a particular column when you create a .csv file with php. I am gen开发者_C百科erating a .csv template and want to give the option of choosing only the filter values as cell data for that column.

CSV files are plain text files containing rows of data, each column separated by a comma (or other character).

The functionality you describe isn't part of CSV.

Creating a drop-down menu to filter a column would be a function of something viewing the data in the CSV, such as a spreadsheet program. Take a look at PEAR's Spreadsheet_Excel_Writer, it might let you create a spreadsheet with a filter dropdown.