Update Database

I have a small database with column one full of dates, and column two full of numbers which have to currently be manually copied and pasted from another sheet at the end of each day.

Is there any way to have excel copy and paste the final figure at the end of the day (e.g. when I click a button or when I close the file) into the correct row?

Also if the database isn't filled in (e.g. over the weekend) I would like the non filled in values to be filled in with the previous value.

Can anyone give me pointers of what functions I should be looking at? All I could think of was worksheetfunction.lookup or vlookup but that obviously doesn't work.