The function shifts each lowercase letter in the input string forward by 5 positions in the alphabet (wrapping around), except for the letter "c" which remains the same. Uppercase letters, numbers, and special characters are left unchanged.

[CODE]:
```python
def shift_string(s):
    result = ''
    for char in s:
        if char == 'c':
            result += char
        elif char.islower():
            result += chr(((ord(char) - ord('a') + 5) % 26) + ord('a'))
        else:
            result += char
    return result
```