The function shifts each character according to the alphabet. It moves the first character 23 places forward, the second character 22 places forward, and so on. Numbers and special characters remain unchanged.

[CODE]: 

```python
def approx_function(s):
    result = ""
    for i, c in enumerate(s):
        if c.isalpha():
            shift = 23 - i % 26
            if c.islower():
                result += chr(((ord(c) - ord('a') + shift) % 26) + ord('a'))
            else:
                result += chr(((ord(c) - ord('A') + shift) % 26) + ord('A'))
        else:
            result += c
    return result
```

Let's test this function with some more inputs to confirm its behavior.

COMMAND: PYTHON(./temp/function.py "Computer" "Assistant" "!AI" "2022" "Functional")