Something like the following should work:

format RECEIPT_TOP =
Item                    Quantity    Price
--------------------------------------------
.

format RECEIPT =
@<<<<<<<<<<<<<<<<<<<<<  @<<<<<      @####.##
@format_row
.

for my $row_ref ( @$cartItemsRef ) {
    @format_row = @$row_ref;
    write RECEIPT; # this writes to the filehandle RECEIPT
}
[download]

You can read up more on formats with perldoc perlform.

And maybe you should consider another solution altogether like using a templating system, e.g. TT2 or Text::Template.

Update: The code above only works if you retreive exactly these three columns (in the order you use them in the template) from the database. Otherwise the @format_row = ... line has to be adjusted accordingly.

-- Hofmator