Populating Client Names with VBA into Existing Sheet (same book) XL97

[thief425]

I am currently working with a "client_roster" list, (Last Name, First Name - column A, column B), another "populate_frequency" sheet that adds column C (visit Frequency Drop down list), and 5 additional sheets (each sheet dedicated to the clients that visit with each frequency).

I need to be able to populate new rows in the "populate" sheet that have the First and Last names injected into columns A & B (respectively) of "populate_frequency" from "client_roster", also continues the drop down list (column C) on the new row.

I need to be able to macro this so that when a tech exports their client list (client roster), they can hit a macro button on the toolbar to inject only their new clients (non-existing in "populate_frequency") into "populate_frequency" on a new row (alphabetical by last name would be even better) that also includes the drop down list in Column C. I have seen enough tutorials to figure out how to inject each client based on their selected frequency into the appropriate sheet for that frequency, I just need to automate the client list sheet -----> populate frequency sheet process.

A simple copy/paste or insert copied.... does not preserve the functionality of column C, the new cell in this column is just a blank cell. One solution that I have now is to preformat column C for 200 rows, and they can just copy their client list into Columns A & B, but this would not work for only injecting new clients, and would require Column C to be re-entered every time they update their client list.

I have a feeling this is some kind of IF loop, but I haven't really used macros enough in Excel to be able to tell the difference.

Thanks in advance, I will check back to see if I need to clarify anything.

Update:

I have been experimenting and reading as many tutorials as I can find. I've almost resigned myself to just pre-format "populate_frequency" with about 1,000 rows with empty drop down boxes in place. However, I would still like a macro to inject (populate) the unique last name and first name columns for each client in "populate_frequency" list. Also, I am trying to ensure that if there are clients who are no longer on the "client_roster", thier row is removed from "populate_frequency".

Any suggestions on macro code to accomplish this?