Regex help in Snowflake

I am trying to write a regex that can replace '[', ']' and '].' with '_' and in cases where ']' is the last character it should be replaced with '' but I am struggling to come up with a regex for it that works in all cases because Snowflake does not support lookahead & lookbehind. My question is, has anyone tried/achieved to do this before? or is it impossible and I should just give up?? Eg: - look_behind --> look_behind_0 - look_behind_positive --> look_behind_0_positive_1