Yes, POINTER is a Scrabble word!

Letter values in Scrabble US: P 3, O 1, I 1, N 1, T 1, E 1, R 1.

Is it a valid word?

POINTER is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a mark to indicate a direction or relation
an indicator as on a dial
(computer science) indicator consisting of a movable spot of light (an icon) on a visual display; moving it allows the user to point to commands or screen positions
a strong slender smooth-haired dog of Spanish origin having a white coat with brown or black patches; scents out and points to game

Also: spanish pointer.