I also would like to post the link from microsoft for the issue of compatibility I encountered with OEC / DDE.
For example In Excel 2016 and 2013, conditional formatting can contain up to sixty-four conditions, but in Excel 97-2003, you will see the first three conditions only, etc…
There is a lot of information on the link but again, it would be best to have a direct contact and/or
an answer from GAIN excel DDE product specialist.
Getting the most compatible standalone EXCEL version is key to avoid future costly mistakes.