Getting directory from PageFiles folder of EPiServer

I'm having some thoughts about how the EPiServer PageFiles system work. When I get a global file it's simple to get the correct directory, I just write:

var dir =VirtualPathHandler.Instance.GetDirectory("~/Global/myfolder/",true)

But when I want to get files from the PageFiles folder it gets tricky for me. The path in the EPi backoffice upload says it is PageFiles/myfolder, but this doesn't return any folders

var dir =VirtualPathHandler.Instance.GetDirectory("~/PageFiles/myfolder/",true)

Now I see that files are saved different for each page, one page has the path /PageFiles/361/myfolder/ and another page has the path /PageFiles/65/myfolder/. All I want to do is be able to write

var dir =VirtualPathHandler.Instance.GetDirectory("~/PageFiles/myfolder/",true)

but to get any folder I have to write (for instance)

var dir =VirtualPathHandler.Instance.GetDirectory("~/PageFiles/65/myfolder/",true)

What is the correct way to get a PageFiles folder so I can access all files in it?

BTW, this is EPiServer 6.0