I need to automate existing excel spreadsheets that we use for bills
of quantities. The sheets contain items, rates, quantities and totals
with various reports and monthly payment columns. The problem is that
the system becomes elaborate and easily breaks. It is difficult for
other users to work on the sheets because they are not sure how the
links and formulas work.

One solution is to abandon Excel and write a database program but
this
take the Excel feeling away and users will not be able to add their
own special reports or formulas. I thought it should be possible to
write a database program (using VBA) with Excel as the front-end.
This
will enhance reliability but retain flexibility compared to Excel
alone.

Is it feasible to have Excel as a front-end ("form") linked to the
database data (in Access) and to be able to add, delete, edit and
link
the data? All this must happen while the database and business rules
are enforced.