Excel 2007 : Fill gap between dates

Hi all,

I was wondering if the following is possible:

column A contains dates (every day of the year) and upon sheet activation excel automatically (vba code) goes to the current date.
column B contains numeric values (weight)

every day one should enter the current weight.
that's the ideal situation. But what if you forget a day.

what I'd like is that excel sees that yesterday and/or days before that are empty and then automatically fills the gap between today and the last previous entry with that last entry.
further more, in column C it should say "automated entry" for those cells.

Does that make sense?