Most things you can merge from have an absolute maximum of either around 127
or 255 columns. If you have a larger number of columns, the chances are that
the only way you will be able to merge is if the data is in comma-delimited
format. If you can put your two Excel sheets back into one, and export your
data to .csv format, then try using that as your data source, you /may/ have
more luck. If .csv does not work, try either opening the .csv file in Word
and saving it as a .doc file, then using that, or select all the data in
Excel, Edit|Copy, then in a blank Word document, Edit|Paste Special and
select "Unformatted text" as the format.

You may need to do more if for example you have multiline data in Excel, or
your data contains characters that Word thinks are delimiters (e.g. tab,
comma, double quotes)

Peter Jamieson