The Excel Bitwise functions convert the supplied integer value(s) to binary form and then perform an operation on the individual bits.
The result is then converted back to an integer value before being returned.
Further information on Bitwise operations is provided on the Wikipedia Bitwise Operation Page
The Excel BitLShift function returns a supplied integer, shifted left by a specified number of bits.
Note: the BitLShift function was only introduced in Excel 2013 and so is not available in earlier versions of Excel.
The syntax of the function is:
where the supplied arguments are:
number    The number that you want the operation to be performed upon (must be a positive integer). 
shift_amount    An integer value, specifying the number of bits by which the supplied number is to be shifted. 
Formula:

Result:

DecimalBinary Conversion
If you want to work through the stages of an 'LSHIFT' operation you can use the Excel DEC2BIN and BIN2DEC functions to convert between decimal and binary forms.In the above example:
Formula:

Result:

In the above example:
Further information and examples of the Excel BitLShift function are provided on the Microsoft Office website.
#NUM!   
Occurs if either:

#VALUE!    Occurs if one or both of the supplied arguments is nonnumeric. 