I don't recommend that. It's an Alienware card. If you're going to replace the card, get a MSI card.
The problem is that you don't know if the board or system BIOS will accept the card. Even if it's the same connection interface, there are likely firmware issues to consider.
Also, external monitors are routed to the Intel CPU, not the video card, so upgrading the GPU won't change your GT70's current capabilities. That comes down to the iGPU and chipset instead.