unfortunately, the Warp tool is not supported in PSE products, so you have to come up with a work-a-round... I've used the Wave Filter & the Liquify Filter to achieve the same effect, but it is time-consuming & difficult - also, PSE does not have "Create layer" function either... so you have to create your own drop shadow layer to begin with...
There is a basic tutorial
HERE on how to get lifted corners in PSE, this was one of the first tutorials I used when I started out with PSE. Scroll about half-way down for the
Custom Lifted Drop Shadow - there are other tips & tricks there, too! 