I don't usually help Prius owners, but I'll make an exception in this case.

Most two-line displays use $80 as the first location on the first line, and location
$C0 as the first location on the second.

When you give the command $FE,1, you are actually performing two operations in one command: clearing the display and setting the first display address to $80. To write halfway down the first line, write to $88 ($FE,$88). To write halfway down the second line write to $C8.
Note that you can send $FE,1 "string" and later write $FE,$88 "string2". The second write won't erase the first string that you wrote. Your display will now show 'string1 string2'