Multplication math in field selection breaks select

The asterisk (*) is used in field grouping, but the output code is not specific enough about which asterisks to match. This is supposed to match a column selection such as:

array('type' => 't.*')

And return all fields in the table with alias t as an object. However, if I was to select a column such as:

array('date_created' => 'EXTRACT(EPOCH FROM date_created) * 1000')

The SQL generator will get confused and thinks this is a field group selection, which it is not. The use of * should be pretty strict so this code needs to be updated to only select asterisks which are preceeded by words and a dot, such as table.*.