In Excel 2010, the Loginv function has been replaced by the Lognorm.Inv function, which has improved accuracy.
Although it has been replaced, the Loginv function is still available in Excel 2010 (stored in the list of compatibility functions), to allow compatibility with earlier versions of Excel.
However, the Loginv function may not be available in future versions of Excel, so it is advised that you use the Lognorm.Inv function if possible.
The Excel LOGINV function calculates the inverse of the Cumulative LogNormal Distribution Function of x, for a supplied probability.
The syntax of the function is:
Where the function arguments are:
probability    The value at which you want to evaluate the inverse function. 
mean    The arithmetic mean of ln(x). 
standard_dev    The standard deviation of ln(x). 
The above chart on the right shows the Inverse LogNormal Cumulative Distribution Function of x. The mean of ln(x) = 2 and the standard deviation of ln(x) = 0.2.
If you want to calculate the value of x, for a probability of 0.3, this can be done using the Excel Loginv function, as follows:
This gives the result 6.653346076.
For further information and examples of the Excel Loginv function, see the Microsoft Office website.
If you get an error from your Excel Loginv function this is likely to be one of the following:
#NUM!   
Occurs if either:

#VALUE!    Occurs if any of the supplied arguments is nonnumeric. 