Hi Julia,
the post doesn't say how much coding you have done with Access, so I am
guessing about how much code and explanations to put in here.
--for the click event of the cmd button put code something like this:
   DoCmd.OpenForm "frmOwner", , , , , acDialog

--this will open the form that has the combo for project owner and the main
form will wait until  a user closes frmOwner.
--instead of closing frmOwner you can just hide it so that you can get the
user's choice from the combo
--put a save button of frmOwner
--code its click event   me.visible = false
--now frmOwner will be open but invisible
--to get the user's choice put code something like this
--    with forms!frmOwner
           if len(.cboProjectOwner) >0 then
               strLinkCriteria = "[OwnerID] = " & .cboProjectOwner & ""
           else
           end if
   end with

so we have something like below:

Private cmdGetProjectOwner_Click()
Dim strLinkCriteria as string

   DoCmd.OpenForm "frmOwner", , , , , acDialog
   with forms!frmOwner
           if len(.cboProjectOwner) >0 then
               strLinkCriteria = "[OwnerID] = " & .cboProjectOwner & ""
           else
           end if
   end with
   docmd.close acform, "frmOwner"
   docmd.openform "frmProject", , ,  strLinkCriteria
   docmd.close acform, Me.name

End sub

** if OwnerID as a text field then use
   strLinkCriteria = "[OwnerID] = """ & cboProjectOwner & """"

frmOwner is the name of the form with the combo
frmProject is the form that opens with the projects from that project owner
OwnerID is the bound column of the combo

Jeanette Cunningham