Yes, it's possible. The details of how you pull the data in will vary, but when the record is imported you can have a field that automatically logs the time.
Field name -- TimeStamp
Data Type -- Date/Time
Default value -- =Now()
"Can these be entered into access directly or will Access have to use the Excel sheet"
gee, that is a loaded question ... depends on how you read the data. Oh, you WILL have to read the Excel sheet to get the calculations -- or you could put the calculations into Access ... but Excel is sometimes easier in that respect so you will most likely want to read what Excel has calculated.
I think I may have to leave this til later, I have discovered that what I want to do may create 4million plus entries per day and doubt that Access will handle that, looking at the specs, at least not too many days of it anyway.
Thanks to everyone for the help I will revisit this later with a revision of what I want to achieve and concentrate more on the Excel development at this time.