If you want to display the country flags as markers on X Y Scatter Chart. Snapshot below:

Steps
1 Download the country flags and save them in a folder
2 Make sure you name the flags as labels or series name
3 Run below macro

Sub custom_markers()
Dim srs As Series
Dim cht As Chart
Dim mapfolder As String

' make sure you save the maps with series name
mapfolder = "C:\Users\admin\Desktop\Flags\" ' folder in which i saved all the maps

' change chart name here
Set cht = Sheets("Sheet1").ChartObjects("Chart 1").Chart

' download the maps or shapes and save them in a folder
' I have downloaded maps from this site : http://www.free-country-flags.com/flag_pack.php?id=1

'run a loop to import flags to markes and display them on charts

For Each srs In cht.SeriesCollection
srs.MarkerStyle = xlMarkerStylePicture
srs.Format.Fill.UserPicture (mapfolder & srs.Name & ".png")
srs.Format.Line.Visible = msoFalse
srs.MarkerForegroundColorIndex = xlColorIndexNone
Next srs

End Sub

Download working File https://app.box.com/s/ulyhg0etinlsqlz88uyr