There is actually 2 different ways to shift DINT in a file.
Input trigger is some pulse.
Shift from Bottom of file to top, only need 1 copy statement
You would mov whatever number into the last word, then as you execute the copy statement, the value would move 1 spot up in file.
Shift from Top of file to bottom, you need 2 copy statement.
Mov a value into first word.