have you exported the .dat files from SQL, if not then you can only restore them back into SQL. Which will over write the whole DB for that file.
If you've exported it from SQL, then if you go to the import. It ask's you what format the files are that you want to import, if you notice in the SQL import screen where you browse the type of files you have a list.
TABLE -> ALL TASKS -> IMPORT DATA
This will bring up the wizard.
First you need to change you data source, this is the type of file you are trying to import into SQL. Once you have choosen the correct file format, it will ask you to show it where the files are stored. Once you've done the first part of the import you go onto the destination for the file.
The destination doesn't need to be changed as this is SQL, so leave it alone. All the rest is self explantry.