First of all you will need a real-time quotes provider that has DDE export enabled. In my case the real time provider is ProRealTime. Usually when testing the DDE on the local machine the syntax for the last price of EURUSD is prtdde|’9_EURUSD’|Last as described in the DDE section of ProRealTime manual.
So, the question is “how can I propagate the quotes into the network ?”. The answer is : “using network DDE”.
1. Start the NetworkDDE and NetworkDDE DSDM services on the machine where the real-time provider runs and on the client machine ( where you want to export real-time data).
2. Declare your local DDE provider on the server machine as being “shared” : Run->ddeshare.exe->DDE shares –> [Add New Share] and fill in the dialog box as in the image below: 
3. In the same application (ddeshare) Declare the share as trusted. 
4. Start Ms Excel on the client host and insert the following string in a cell: =’\\SERVERNAME\NDDE$’|’prortdde$’!Last where :
- SERVERNAME is the hostmane of the real-time provider machine ( or DDE Server) .
- NDDE$ is a required string which identifies the DDE shares on the server
- prortdde$ is the name of the share set up at step 2 ( which is a shortcut for prortdde|9_EURUSD
- Last is the item needed from 9_EURUDS topic
For more information check this link.
[EDIT 25 Jan] It seems that NetDDE is no longer supported by new versions of Windows. Check this link !
