Fixed checkbox column in EXTJS panel(no horizontal scroll only for checkbox column)

Team,

Is Anyone aware of disabling horizontal scroll on checkbox column(1st column in grid) checkbox column remain fixed and other column's scroll properly remain working.

I tried

     bodyStyle:'overflowY: auto',

     autoScroll:false,

     setAutoScroll:false,

on particular checkboxSelectionModel and try to override property but it's not working.