Let the display do the hard work by using the Right to Left "Entry Mode".
Then just change the custom characters.
No changes are required to the include file.




Code:
X  VAR WORD

;----[Initialize bargraph]------------------------------------------------------
X = 0
@   BARgraph  _X,   1,   1, 20,   512,  lines
    LCDOut $FE,$48,REP $15\8                  ; Custom char 1 - 1 line     |
    LCDOut $FE,$50,REP $05\8                  ; Custom char 2 - 2 lines   ||
    LCDOut $FE,$58,REP $01\8                  ; Custom char 3 - 3 lines  |||

;----[Main Program Loop]--------------------------------------------------------
MainLoop:
    FOR X=1 TO 512
        PAUSE 10
        LCDOUT $FE,$94,DEC X,"    "

        LCDOUT $FE,$04  ; Set Entry mode Right to Left
'@      BARgraph   Value, Row, Col, Width, Range, Style 
@       BARgraph      _X,   1,  20,    20,   512,  lines
        LCDOUT $FE,$06  ; Restore Entry mode Left to Right

    NEXT X
GOTO MAINLOOP
Of course, I'm assuming the Newhaven display can actually do that.
Normal LCD's can.