Excel Formula and calander

This has 2 parts to it.
First, I need a formula for: I have a dropdown list in cell h38 (yes or No)
If H38 is Yes then I want the formula =sum(e38*G38)*.07(E38*g38)
If Hs8 is NO then I want the formula =sum(e38*G38)

Secondly, I have multiple cells that need a date inserted. Is there a popup calander ,3rd party or otherwise that I could use, so that when a person clicks on that cell, they then can choose a date on a visual calandar?

Thankyou