Sorry to keep posting... but I have just put in the operator 'AND' so the code now reads...
DoCmd.OpenForm "Frm_Company", , , "CompanyRef = " & Me!ListCompany And "Forms!Frm_Company!SubFrm_Contacts", , , "ContactRef = " & Me.ListCompany.Column(1)
However I am now getting an error for a 'Type...