How to intercept the TAB key press to focus on a check box which becomes enabled after TAB key was pressed?

When we press the TAB key we change the focus to the next control in the given tab order. In my case when I click on a check box (say X) then after pressing Tab button the control is going on a text field instead of going on next check box (say Y) which was previously disabled and became enabled after the tab button was pressed. I want the control to move to the Check box Y. Thanks.