Your code is probably for 4 digit 7 segment display where the segments is driven via 74HC595 shift register, and the common anodes via transistors directly from MCU or for multiplexing a bare display whitout driver right
wrong , my code is for your circuit but using a different pic chip . I don't have a 12f1840 on hand but I cannot see any reason for it not to work on that chip . if you use the right pins.
your code is for common anode mine common cathode the commented lines can be changed to suit


COMF _segment,W for common Anode becomes MOVF _segment,W
COMF _d_pointer,W for common Anode becomes MOVF _d_pointer,W
ie the current is reversed in the display