Those dlls are CE code, they will not run on your web server. 

The MK500 comes preloaded and prelicensed with our PocketBrowser, which gives you the ability to access the scanner using meta tags and/or JavaScript from your web app (you do not need or want those dlls).

Take a look on the support site and download the relevant version of PocketBrowser to your PC so you will have the help file so you can see how to use it. I think it was a 2.X version on the MK5, but it's been a while.
https://portal.motorolasolutions.com/Support/US-EN/Search?searchType=si…
I will paste in below some code I have used to show how this can work on an MK500.  If you point pocketbrowser to this page on your webserver, you should see the scanner working.

 
    var Generic = new ActiveXObject("SymbolBrowser.Generic");

    function doSoftScan()
    {
     Generic.InvokeMetaFunction('scanner', 'start');
    }

    function doScan(data)
    {
     bcode.innerHTML = data;
     doSoftScan();
   }