I am in the same boat as you, I own a Nikon CoolPix 5000 and want to increase my zoom, but I’m limited as in options due to the camera. I have decided that it wasn't worth it to buy the adapters and zooms lens and instead just buy a Nikon D100. While this may seem like the expansive option (and it is) I think it is worth having a DSLR because of versatility it offers.
For example you can add those huge telephoto lens and funky lens like fish eyes and get quality results. Also by going with this option you can use your old camera as a backup and when u want to take interior pictures or when its just better to have a smaller less flashy camera that attracts less attention.