Need EXCEL to include weekends in date range 2009 onwards

Hi , I have 2 columns of data A/B , however I need the date column to include weekends , along with a copy of previous PX_LAST price

For instance , current state is this , it skips through and ignores 10/01/2009 & 11/01/2009

Current

Date PX_LAST
02/01/2009 2.221
05/01/2009 2.212
06/01/2009 2.177
07/01/2009 2.181
08/01/2009 2.159
09/01/2009 2.15
12/01/2009 2.144
13/01/2009 2.123
14/01/2009 2.115
15/01/2009 2.117
16/01/2009 2.11
19/01/2009 2.12


Required ... it includes the weekends , and also updates column B with the Fridays PX_LAST

02/01/2009 2.221
05/01/2009 2.212
06/01/2009 2.177
07/01/2009 2.181
08/01/2009 2.159
09/01/2009 2.15
10/01/2009 2.15
11/01/2009 2.15
12/01/2009 2.144
13/01/2009 2.123
14/01/2009 2.115
15/01/2009 2.117
16/01/2009 2.11
17/01/2009 2.11
18/01/2009 2.11
19/01/2009 2.12

This is 9 years worth of date , 2200 rows approx , so would be really helpful if there was some kind of autofill function that could be utilsed .. tks in advance

SF