You could use your pot to dip the water, then pour it into the Platy. Of course, this depends on how you pack - your pot may not be convenient to get at.
Could you carry a ziploc bag to fill, then pour into the bottle? (Just a theoretical suggestion.)
Since I use a Katadyn mini-filter, with a Platy-link attachment, I don't have any direct experience with your problem. However, I got tired of kneeling by the creek, so I got a collapsible coated-nylon bowl. I fill it in the stream (it molds wonderfully into shallow spaces, etc.), then carry it to a convenient, comfortable log or rock to filter. I've also used a ziploc with some success to gather water, but the idea broke down when I tried to stand it up: it flopped over and spilled.
But I digress. If you've got anything that's handy, light, and can pour, you may have a solution.