When importing data into Excel extra characters can sometimes be brought along with good data, and these extra characters can cause problems if the data is to be used in formulas or other calculations.
One way to get rid of the unwanted data is to use Excel's REPLACE function.
REPLACE will not only remove the bad stuff but it will also replace it with good stuff.
In the process, it will allow you to specify exactly how many characters of data you wish to replace.
For more information on this handy member of Excel's text function contingent, read the tutorial on the REPLACE Function.