you just need to get a 9 pin D-SUB to HD15 Pin adapter. Image quality will not be capable of anything better than what the 9 pin outputs, but it "should" work.
Otherwise as stated, a dedicated graphics card would be better. Depending on your needs, it probably doesn't need to be anything big new or fancy. Could get an older cheap low profile/low power graphics card that doesn't require any power cables and gets all power from motherboard and just make sure it has the necessary outputs to support your monitor of choice.
If the monitor supports a DVI connection alongside that VGA then you'll have a better time picking up a graphics card for that.