custom logo for internet explorer

Hello All,
I am trying to place a custom bitmap image in internet explorer under GPO
for internet maintenance. When I specify the path of the bmp file it tells
me "please specify an existing path" and does not allow me to change the
custom logo. Is there a particular directory in which this file should be
placed. Also, I have tried both a local path and UNC path.
Any help would be appreciated.
Thanks,
Altria