Function ReadBinaryFile(FileName)
Const adTypeBinary = 1
Dim BinaryStream
Set BinaryStream = CreateObject("ADODB.Stream")
BinaryStream.Type = adTypeBinary
BinaryStream.Open
BinaryStream.LoadFromFile FileName
ReadBinaryFile = BinaryStream.Read
End Function

Set objNewUser = GetObject("LDAP://cn=some,ou=adspath,dc=domain,dc=local")
objNewUser.GetInfo
objNewUser.Put "thumbnailPhoto", ReadBinaryFile("image.jpg")
objNewUser.SetInfo