Actually, I take it back, you could make one in Premiere, sometimes genius strikes me 😉
1- File > New > Transparent video
2- Apply the Timecode effect to it.
3- Now the good part… Use the offset setting to bring your timecode into the negative, how ever far you need it to be so that it counts down.
4- Apply the crop effect to get rid of the digits you don’t need, such as frames or hours.
Cheers,
Vince