I don't know why anyone would would attempt BRFSS or NHANES or similar data with Excel. Just getting the weights applied correctly can be a nightmare. If you go to the CDC websites for the data you should find SAS code to read text files into SAS or SAS data sets in transport format; helper code like Proc Format and typically some examples of basic summary statistics.
Start with the free online SAS Programming 1.
If you are working with any of the public use data sets look for the SAS code, code books/data dictionaries and example analysis code.
You can find a large number results just putting "SAS BRFSS" or "SAS NHANES" or similar into any search engine. Though again if using those I would start on the CDC website for project specific.