Method One,
Starting Excel2010, click the Options button on the left side of the File tab interface, as shown in the picture:
Then open the Excel Options dialog box, click the Advanced tab, enter the path you want to open the file in the "Open all files in this directory at startup" text box in the General bar, and click OK, as shown in the figure:
Method Two,
Find a folder named XLStart on your computer by using the Windows Search feature, as shown in the figure:
You can generally find more than two folders of the same name, and you will be able to open them automatically at startup by storing the files you want to open in any folder.
Note: If you are using method two can not open the file you want, because your computer installed more than one version of Excel, different versions of its corresponding XLStart folder is also different, find the appropriate folder to store it.