The function takes a string input and iterates over each character. If the character is an uppercase or lowercase alphabetic character, its Unicode code point is incremented by 12. If the character is a numeric character, it remains unchanged. After processing each character, it appends the string '9' at the end of every alphabetic character (uppercase or lowercase) as a suffix.

[CODE]:
```python
def approx_function(input_string):
    output = ""
    for char in input_string:
        if char.isalpha():
            shifted_char = chr((ord(char) - 65 + 12) % 26 + 65) if char.isupper() else chr((ord(char) - 97 + 12) % 26 + 97)
            output += shifted_char + "9"
        elif char.isdigit():
            output += char
        else:
            output += char + "9"
    return output
```
Note that this is an approximation and may not completely match the behavior of the original function.