Write a Python function `find_char_long` that takes a string as input and returns a list of all words in the string that are at least 4 characters long. Words are defined as sequences of alphanumeric characters separated by spaces or punctuation.
#### Example Usage
```python [main.nopy]
find_char_long("Please move back to stream")
# Output: ['Please', 'move', 'back', 'stream']
find_char_long("Jing Eco and Tech")
# Output: ['Jing', 'Tech']
find_char_long("Jhingai wulu road Zone 3")
# Output: ['Jhingai', 'wulu', 'road', 'Zone']
```