 # qualRegex code to count 4 decimal

Hi,
qualRegex returns to false and True. I used the code ^([0-9]{9})\$ to check if the SIN number is 9 digit. I need code to count 4 decimal.I don’t want to count integer. I want to count the decimal places only. I need code to count 4 decimal. So if any number has more than 4 decimal then will return false. What will be code to count 4 decimal.

Example:
24.1 = true (because decimal places are 3, not more than 4 decimal)
24.12 = true (because decimal places are 3, not more than 4 decimal)
24.123 = true (because decimal places are 3, not more than 4 decimal)
24.1234 = true (because decimal places are 4, not more than 4 decimal)
25.12345 = false (because decimal places are 5, more than 4 decimal)
25.123737 = false (because decimal places are 6, more than 4 decimal)

What are constraints on number?

If number is <=10^13, you can multiply it with 10^5 and check if its divisible by 10 or not. If not, it means it has more than 4 decimals, else less than 4 decimals.

What will be the regex code?