What I've done in cases like this is to import the spreadsheet to an interim
table that duplicates the spreadsheet structure, and then run an append and
or update query to move from my interim into the 'real' table
My 'source' spreadsheet might contain for example duplicate records, and I
can locate and update or add new in code so I only get one instance of each
particular set of data.
I add excel as a reference in Access VBA, which make it easier to get to the
first line with data. - It allows you to open the spreadsheet and navigate by
row and column, which avoids problems when the source spreadsheet has been
given a title and you can't use linked table manager.
You can select which row to start from, and even open sheets that are
password protected.
The excel reference also provides a usable method to get users to select the
spreadsheet now that Microsoft have decided that the Common Dialog boxes are
too good for common people. (They don't work with different versiosn of
operating system, so even though you may well only have the one operating
system, you still can't have the common dialog box that goes with it -- not
even for ready money)