For a general approach, you can try the following:
a = [[1],[2],[3],[4],[5]]
b = np.zeros((8, 1))
index = [0, 1, -3]
# convert negative index to positive index : -3 to 5
zero_indexes = np.asarray(index) % b.shape[0]
# [0, 1, -3] -> array([0, 1, 5])
all_indexes = np.arange(b.shape[0])
zero = np.isin(all_indexes, zero_indexes)
# insert 'a' to not_zero index
b[~zero] = a
print(b)
You can use np.insert.
a = [[1],[2],[3],[4],[5]]
# ---^0--^1--^2--^3--^4
# two times insert in index : 0
# one time insert in index : 3
b = np.insert(np.asarray(a), (0, 0, 3), values=[0], axis=0)
print(b)
Output:
[[0]
[0]
[1]
[2]
[3]
[0]
[4]
[5]]
0should be inc?