Is it 44780 based LCD module, If yes, than I have written code for this in one of my project recently.

For moving to the first line you have to define the address in a command.

for Example:
MOV LDATA,#0C4h ; mov cursor to the next line char first.
CLR RS ; tell LCD that this is a command
ACALL LCD_SNT
ACALL WAIT_4MS

Where is LDATA is equates to the memory reserved location where I keep any character to be sent out to the LCD.

#0C4 is the address of the character placement in the next row. In your program you can use from #00 to #0F, 00 for 1st character in first row and 0F is last character in the first row.

I hope above will help you.

Rauf / Microlink