Source Worksheet to Database Worksheet so Source can be reused w/o changing old Db entries

I have one worksheet into which I enter a date and some data. I want that data to fill into a set of cells in a different worksheet such that this data is stored in those cells ongoingly. Then, I want to be able to go to the original worksheet, change the date and data, and have that change not effect the cells which gathered the original date/data combo, but go to a different set of cells in the database worksheet to capture the new date/data entered into the original worksheet. Thoughts?

Attaching file through Go Advanced.

Source worksheet is tab --> Daily Plan

Database worksheet is tab --> M MD

User enters date into the M MD tab manually, it uses VLOOKUP to enter the Actual from source worksheet into the Follow-Up cell associated with the names in the Source Worksheet. I then want to be able to have this data remain in M MD when the user goes back and changes the Daily Plan worksheet.

Still need help on this one...anyone have an idea?