Ben,
Unfortunately an import map will not handle timescaled data, which is
what you need. There are a couple of methods for transferring the data
that I am aware of; there may be more.
If you do not have a large amount of data, for example, actual daily
hours were started in Excel but now you have decided to enter them
directly into the Resource Usage view. Meanwhile you need to get the
existing data transferred. A simple but somewhat laborious method is to
copy and paste the data. This only works effectively if the Excel
Worksheet can be formatted to look like the Project Resource Usage data.
A second method is to use VBA to transfer the data. this works best if
there is a large amount of data or you need to make the transfer on a
regular basis. Once the code is set up, transfer is very quick and
pretty much error free. I my opinion, VBA is the preferred method.
I don't know if Project Central or one of the Server versions of Project
would make the task quicker or easier. I've never used either one.
Hope this helps.
John