Hi dear my friends. Finally I found a way for dumping spl. This is a known way, but nearly no one knows much. And there isn't any tutorial about it.
1) Run Windows Mobile Rom
2) Install SPLDumper app for PC from bottom of this post (credits symbuzzer)
3) Plug your phone in activesync mode to PC via USB
4) Run SPLDumper.exe, it will created "spl.nb" file on your desktop.