Sikpupi,
I am not so sure what you are asking. If you are using WMP to convert MP3s into the format that will play on CD Players and it is not working on your player, I would try it in other players. Also use CD-Rs and not CD-RWs since you have a better chance with older players using CD-Rs.
Now if you are keeping them in MP3 Format, then just use Windows Explorer to Drag and Drop, but they will not play in most players in that format.
Take Care,
Richard