Well first, the convention for talking about adapters is <source> to <display>. So an adapter for connecting your DP computer to your VGA display is a DP-to-VGA adapter, not VGA-to-DP. Most adapters only work in one direction, so proper terminology does matter.
Yes, "analog" is the input that you want.
It's probably a better idea to use a DisplayPort to DVI adapter instead. Not sure why the DP to VGA adapter wouldn't be working though.