SCENARIO

A factory production line uses RSLINX software to gather data from PCI
cards and expose it through DDE.

An Excel spreadsheet consumes this via Copy and Paste of the link from
RSLINX.

This spreadsheet is then saved in XML format.

This XML file is in turn consumed by a web page that displays the data
gathered by the RSLINX software. The web page is set to refresh at 30s
intervals.

PROBLEM

The Excel spreadsheet is updated in real time (you can see the numbers
change as the data is pumped in by RSLINX), but of course the XML file
is not updated until the file is saved, so the data on the web page is
not updated unless and until the spreadsheet is saved.

The client obtained a cheap "autosave" Excel plug-in to save the
spreadsheet periodically, but it doesn't work reliably.

DESIRED SOLUTION

Remove the Excel middleware and replace it with an applet that will
consume the DDE data directly and transform it into the XML file
required by the web page. I was thinking of a windows service or
something similar. They don't want a console application/scheduled
task solution. The budget is TINY.

ACCEPTABLE SOLUTION

A reliable means of saving the XML file periodically. The most
important word in that sentence is "reliable". A background timer in a
macro? A save triggered by a cell's Change event firing?