Ok. that might look a bit daunting at first but its not too hard to understand. So on your combo box go to its properties and create an event procedure on the afterupdate event. Then type in the above code replacing 'Command14_Click' with the whatever yours is called. eg if u called your combo box 'mycombo' then you wold replace 'Command14_Click' with 'mycombo_afterupdate'.
This code opens up a form called the_name_of_the_form_you_want_to_open_here and uses a filter to bring up the selected criteria
stLinkCriteria = "[Name of Program]=" & Me![Combo4]
however, it will only work if u r dealing with a bound form. If you do this when the next form opens, after some one has selected a value from combo4, if you look at the form in design view and go to the form's properties you'll see that the filter attribute will have [Name of Program]= <whatever> where <whatever> wil be the value of the combo box.