VBA forcing to a DDE server to refresh

Hi there.
I have a spreadsheet receiving data (stock quotes) from a DDE server.
However this DDE server send quotes into Excel just when prices changes.
Sometimes, when the stock markets are calm or quiet the prices don't change for "long" period of time (I mean, for more than 2 minutes).

Here is my problem:
I need that DDE server send quotes information each short periods of time, for example each 5 seconds.

It seems that I need to "force" to the DDE to send information into the spreadsheet even thought the prices don't change.

I have tried to do this with a VBA macro using Ontime and the VBA UpdateLink methods:
ActiveWorkbook.UpdateLink Name:=ActiveWorkbook.LinkSources

But however this sentence line doesnt "force" to the DDE send to send a quote.

Any Idea if this is possible to do with a VBA macro.?
I don't know if the VBA DDERequest method can "force" to the DDE server to do a refresh

Best Regards
Hernan