I am importing a table into Excel. The table is text and has columns which
include fractions such as 1/8, 3/16, 5/32, and also composite fractions such
as "1 1/8", "2 3/4" (but without the quotes).

Excel thinks these are dates and autoconverts them to a date serial number.
Once this happens there is no way to recover the original fractions.

I have tried preformatting the columns where the data will end up as
'Fraction' format, and 'Text' format but that makes no difference.

Is there a simple way of stopping this behaviour? At present I am manually
pre-processing the data in Word to put quote marks around the fractions so
they are imported into excel as text. I can then use formulas to re-create
the deired numerical fractions.