WiX v5 is here! Let us help.

DDE connections

Shell connections using DDE (Dynamic Data Exchange) can be set up as follows:

<ProgId Id='Program.xyz' Description='Program handling .xyz' Advertise='yes'>
  <Extension Id='xyz' ContentType='text/sql'>
    <Verb Id='open' Sequence='1' Command='Open' Argument='"%1"'/>
  </Extension>
  <Extension Id='xyz0' ContentType='text/sql'>
    <Verb Id='open' Sequence='1' Command='Open' Argument='"%1"'/>
  </Extension>
</ProgId>

<Component Id='regSetup' Guid='YOURGUID-6D8A-4AE2-9D9F-3E074F13A029'>
  <Registry Root='HKLM' KeyPath='yes' Key='SOFTWARE\Classes\Program.xyz\shell\open\ddeexec'
    Type='string' Value='[\[]open("%1")[\]]' />
  <Registry Root='HKLM' Key='SOFTWARE\Classes\Program.xyz\shell\open\ddeexec\application'
    Type='string' Value='Program.xyz' />
  <Registry Root='HKLM' Key='SOFTWARE\Classes\Program.xyz\shell\open\ddeexec\topic'
    Type='string' Value='System' />
</Component>