set maximum value of horizontal srollbar in listbox control

hello.
I’m use horizontal srollbar for slide a total colum of listbox
I’m write code

ValueChanged Event :

ListBox1.scrollPositionX=Me.value

open Event :

Me.minimum=0
Me.lineStep=5

I don’t know How to set maximum value of scrollbar control for a fit slide colum

I once set : " me.maximum = 50"

but scrollbar not fit slide colum

how to ?

thank you very much