Basically you put a number of the item in question in the first slot of a hopper that has its output aimed at a non-container block and something that you're sure won't ever go into the hopper, like renamed cobblestone in the other slots.
Under that hopper you have another that is normally disabled by a redstone signal so it can't pull anything from the first.
Then you have a comparator connected to the first hopper so that it gives a signal when an item is added, that signal turns off the redstone signal which allows the second hopper to remove an item from the first which disables the second hopper again and can also be hooked up to your dispenser.
If the player is standing close enough to the dispenser and has an empty inventory slot the paper would be picked up.
If you want to be absolutely certain that it goes into the inventory you may need to use a command block.
I don't know how unaware the player has to be about what happens when the item goes in, if it was for an auto store one would have a sign warning them to make sure they have room in their inventory.