Removing special characters of a string using function

alter Function [dbo].[RemoveNonAlphaCharacters](@Temp VarChar(1000)) 
Returns VarChar(1000) 
AS 
Begin 
 
    Declare @KeepValues as varchar(50) 
    Set @KeepValues = '%[^0-9a-zA-Z @\.\-]%' 
    While PatIndex(@KeepValues, @Temp) > 0 
        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '') 
 
    Return @Temp 
End

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use ods
;with CR AS(
select issue_id,  stringvalue from ssistemp.jirastage.JiraDroidBugIssueCustomfieldvalue
 where custom_field_id = 10686
)
select
CC=dbo.RemoveNonAlphaCharacters(CASE WHEN (CR.Stringvalue LIKE 'http://prism.qualcomm.com/CR/%'             
     or CR.Stringvalue  LIKE 'https://orbit/CR/%' )
then
replace(replace(CR.Stringvalue,'http://prism.qualcomm.com/CR/',''),'https://orbit/CR/','')
else null end ) into ##temp
from CR