I can't find the Tech Support note now, but about two years ago SAS reported that importing Excel data that included cells with multiple lines of data could result in truncation of the cell data.
So I suggest you carefully check any data from cells of this type.
It's a reminder that Excel is a data presentation tool, and SAS is a data management and manipulation tool, and there are often disparities when you try to the two together.
I'm surprised that DDE has a problem. If I have the time I'll look at reading the Excel data through DDE in bytes. If that's possible then that should distinguish the internal carriage returns from the cell boundaries.
Kind regards
David