Zeiss made a 3=9X40 Conquest that was parallax adjusted to 50 yards.There are still some around. The Nightforce 2.5-10X42 NXS has parallax adjustment to 10 yards. There may also be some of the newer tactical type scopes that have parallax adjustment for close range.

My personal favorite rimfire hunting scope for squirrels is the Leupold VX2 4-12 AO with fine duplex. It is light and will focus to about 25 yards on 12X and closer on lower power.