Sends an item to the DDE server.
DdePoke( service, topic, item, format, resource )
resource := 'value'
Service is the name of the DDE server.
Topic is the topic of the conversation.
Item is the item that must be sent to the DDE server.
Format is the Windows data format of the item.
Resource is the resource that is sent. Only "value" is supported.
NOTE: This method will not report that mandatory parameters are missing.