How to extract a string in between the characters from the string SQL?

Please check with this code, I was used in my project for extracting numeric value

Declare @str varchar(50)= 'userid7f(203001)31f469-NAIsasdsd'

select substring(@str,patindex('%(%',@str)+1,patindex('%)%',@str)-patindex('%(%',@str)-1)
OR

select substring(@str,charindex('(',@str)+1,charindex(')',@str)-charindex('(',@str)-1)

OUTPUT= '203001'