You have two options here that I see.
1. Import the Excel file as is and develop (manual) program that will check each variable type and if not then it converts it to the type and format desired.
2. Convert the Excel files to CSV - using a VBS script, see link below, and then use a standard data import to import all at once. You could also automate this entire procedure if so inclined, to download the file, convert and then import.
http://support.sas.com/kb/43/496.html
Personally, I'd go with Option 2 because I'm lazy...but you can do Option 1. It'll likely end up being a macro and you can use VTYPE to check a variables type. If you do decide to go with Option 1, I would recommend first creating a file with the master variable list and types and use that to drive your program so it's still automated in a fashion.
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