Sends a DDE command to a service.
/dde [-re] <service> <topic> <item> [data]
This sends an XTYP_POKE by defaults unless you specify the -r switch in which case an XTYP_REQUEST is sent, or if you specify the -e switch, an XTYP_EXECUTE is sent.
If you are sending an XTYP_POKE then all four arguments are mandatory.
If you are sending an XTYP_REQUEST then the first three arguments are mandatory.
If you are sending an XTYP_EXECUTE then only the first three arguments are required.