Pin off of a Double Hung window screen

Do you have any idea what this is called. It is a guide pin that holds the window screen in place from a double hung window screen. Obviously it's on top of the screen frame. I need to build some of these screens and I cannot identify or find this part. A typical plunger pin will not work. I need this or something similar that will thread into the top of the frame. Thank you.
Denton