Is there a way to check if user has a specific custom stamp installed?

Hello All, 

Ive been wracking my brain on how to do this and I'm not even sure it's possible through Javascript.

I have a document where I want to have multiple users approve various steps with a custom stamp I've developed. I've done this with buttons coded to insert the stamps in specific locations. What I need is a way to check if the user does not currently have this stamp installed, so that instead of a blank square, it will simply insert the standard "Approved" Dynamic stamp. Something like the below...

if (*AP "customDynStamp" exists in user folder*) {//just an example of what I need
var useThisAP = "customDynStamp"
} else {
var useThisAP = "#DApproved";
}

I've tried using the app.openDoc method to check if the file exists, but I can't use the "app.getPath('app','stamps')" code to find the user's stamp file path within a button. If I create a stamp with the AP and check it afterwards, I see no difference within the properties to determine whether or not it found the image or if it's just blank.

Is this just one of those things that can't be done with code?