metis, I wrote this a while back, you select an image, it converts to base64 and puts it on the clipboard.
Just paste into where ever you need.
Change the path to your image dir.
;Xroot 2011
ClipPut("")
$FN=FileOpenDialog("Pick The Image You Want...","C:My DocumentsImages","Images(*.*)",3)
If @error Then
MsgBox(4096,"","No File Selected.....",2)
Exit
EndIf
$dat=FileRead(FileOpen($FN,16))
$objXML=ObjCreate("MSXML2.DOMDocument")
$objNode=$objXML.createElement("b64")
$objNode.dataType="bin.base64"
$objNode.nodeTypedValue=$dat
ClipPut($objNode.Text)