did you try with command 254(0xFE) first?
by the looks of it, the lcd module is a stand alone product which has its own command register, the cursor position and clear screen etc are part of this register. There is a PIC that has been attatched that also has a command register which is the 0x7c register this is used for controlling the communication speed, splash screen etc..
this is how to set the cursor position from the sheet you downloaded
1)determine the correct decimal position to move to
2)set bit 7 of that number to 1 e.g. 194
3)now transmit special serial character 254
4)finally transmit your cursor position number (194)
(page 3)
All of the extended lcd commands in that box would use 254(0xFE) to work aswell as the commands in the external link below it.