
Step 1 : Download the flags and add them all to a worksheet with country names and flag in two separate columns. For example "Flags" in attached file .
Note All flags should fit within the cell
Step 2
Goto excel option in ribbon(Excel 2007) then click on customize -> all commands -> the choose camera and click on add
you will see camera at top of menu

Step 3 Click on camera then again select any cell and re-size the camera box size .You will see a box like below

Step 4 Create a name range "display_flag" using this formula =INDIRECT("Flags!B"&MATCH(Sheet2!$A$6,Flags!$A:$A,0)) . Snapshot below-

Step 5 Click on camera box goto fx button and type =display_flag see below

Step 6 Select cell A6 and add data validation. choose list and give the reference of all country names listed in "Flag worksheet"
Download the Working File with 226 Country flags https://www.box.com/s/2c3daddbcbe5719f729c
Note: All flags are downloaded from