How to position form elements

Hi,

I've been given a job of making a small alteration to an existing form (CustTable).

In the overview TAB I need to add a check box onto the grid who's selected status is set according to some related data to the customer table. This I've coded fine and works OK.

My problem is the requirement is for the check box to be at the first position on the left of the grid (before customer account). By default it seems to be in the last (far right position). By playing with the value of 'Left' for the check box I can get it to appear correctly when I open the form with the edit option of the design but it appears at the far right when 'Open' is used on the form.

As you can guess I'm very new to this. In fact just started this week and this is the first job I've been given. So I know I'm obviously missing something really really obvious. You may also assume I haven't been given much training before being tasked with this work !

Thanks for any help.