Click on a cell transfer to a different cell on a different sheet

[dkim2586]

Hi so I am a bit new to the VBA coding in excel so I need some major help with this issue. Ok so I have these two sheets, one called "One Key" and the other one is called "Preparation". In the "One key" sheet I want to click on one cell from the "Compound Code" column and then click on one or more cells on the "Code" column and if I press enter after my selection is done. I want the numbers to transfer to my preparation sheet.

I want the user to only select the compound code cell only one cell at a time and they can select one or more on the dilution cell.

So for instance if I click on one Compound code lets say the number "1" and like 3 cells in the "Code" Column next to the dilution column in the "One Key" sheet. On the "Preparation" sheet for the Compound Code column it should have the number "1" listed for 3 rows and for the "Dilution code" column it should have the 3 different numbers that I clicked on from the "Code" column from the "One Key" sheet.

Any suggestions would be helpful thanks!

I attached the file of what my worksheet looks like.