VBA Code open files in folder, copy text to workbook-Next time folder opened copy only new

I have VBA code that works perfect except for one thing. Currently when I click on the button (Process Data) the code opens a folder and copies some text from all the spread sheets that are in this folder, which works great except that files are being added to this folder every day and if i click on the button (Process Data) a second time it brings in all the files I already have and any new ones which will duplicate the ones when I pushed the button the first time. I ended up adding a clear button that would remove all data and then push the (Process Data) to re-populate the spread sheet. I would like to remove the clear button.

My question is how can I change the VBA code so if more files are added the the folder each day that it only looks at the new files that it has not already transfered data from.

I have attached spread sheet.
Can anyone help!

Sorry for late responce, been on vacation.

Trying to test your code, sorry but I'm new to using VBA code. I noticed you mention in a couple places in the code to "change this to an unoccupied cell" not sure what you mean by this? Also at the end of your code you mention "Change this line" (SourceBook.Close True) not sure I understand what to change it too.

Sorry for my lack of knowledge on how to write code.

This works great! Thanks so much.