I want to trim SQL Server strings using some special characters such as "،,.?!؛,،,><=+ـ". 

The SQL server ltrim and rtrim functions only strips the space characters.

```
DECLARE @Str NVARCHAR(100) = N',,,,,!؛Computation+Time, Cost،,.?!؛,،,><=+ـ'
SELECT dbo.SpecialTrim(@Str, N'،,.?!؛,،,><=+ـ')

The result : Computation+Time, Cost

```

Have anyone any ideas in order to implement SpecialTrim function?