If you run WinTest, you can just "type" to the LCD by clicking in the white "edit" box (and you can also use the arrow keys to move around the display). Once the LCD shows what you want, you just send the \009\005 and \009\003 and that becomes the new boot screen.
The code \008 is backspace and code \010 is LineFeed, but code \009 is documented as "not used" (ref: p. 4 section "Display Codes" v1.x pdf doc). What does it do exactly? Do you have an updated document for us to view?