The function takes an input string and adds a fixed value (14) to the first character's ASCII code, leaving the rest of the characters in the input string unchanged. The function doesn't change any numeric characters.

[CODE]:
```python
def approx_function(s):
    if not s:
        return s
    first_char_ascii = ord(s[0])
    if first_char_ascii >= 48 and first_char_ascii <= 57:  # ASCII range for numbers
        return s
    new_first_char = chr(first_char_ascii + 14)
    return new_first_char + s[1:]
```
