Considering you have a VPS Windows Server and want to run an application that requires to have a graphics card having 64MB of RAM, could you somehow simulate that graphics card to run the application or is it inevitable to install a physical graphics card? I thought about utilizing RAM or CPU partially as Graphics Card.
The Application has to choose the particular graphics card to use it.
You cannot simulate a card, if h/w GPU is missing. But it is possible to assign VRAM depending on host's hypervisor. For example in Hyper-V, you can use RemoteFX vGPU with up to 1024MB VRAM.