In most of the galleries js file there is an initial property. This property determines what picture loads first. You could make this value a dynamic one by adding in some js to pull the value from a URL parameter rather than just start at 0.
If you set it up like this you could then link to the page with the gallery on it and just include the URL parameter that your js is looking for and set the value to the image in that gallery that you would like to show.