For anyone interested, the FROM clause is what I needed. This allows me to access the variable from another program.
PROGRAM array_get
VAR
arraySlot: ARRAY[50] OF INTEGER
BEGIN
--Get Array Slot
GET_REG(58,FALSE,slot,temp,STATUS)
coll = arraySlot[slot] MOD 24
row = arraySlot[slot] - coll
row = row DIV 10
SET_INT_REG(60,coll,STATUS)
SET_INT_REG(59,row,STATUS)
END array_get
PROGRAM array_incr
VAR
arraySlot FROM array_get: ARRAY[50] OF INTEGER
slot FROM array_get: INTEGER
BEGIN
--Increment
arraySlot[slot] = arraySlot[slot] + 1
END array_incr