Replace a char with a string dynamically

Try this,

drop table #t
drop table #t1

create table #t (c varchar(1000))
 insert into #t values ('DDXXD4444DDD')
 
create table #t1 (c char(1),val varchar(20))
 insert into #t1 values ('D','SXM')
 insert into #t1 values ('X','DSN')
 insert into #t1 values ('4','MXD')
 

 ;WITH CTE AS (
        SELECT Number,SUBSTRING(c, 1 + Number, 1) [char]
                      FROM   master..spt_values,#t
                      WHERE Number < DATALENGTH(c)
                            AND type = 'P'

 ),CTE_REPLACE AS (
        SELECT Stuff((SELECT ' ' + VAL 
              FROM   (SELECT [NUMBER],VAL FROM CTE A INNER JOIN #T1 B ON A.[CHAR]=B.C) X  
              FOR xml path('')), 1, 1, '') VAL
                                
 )
 SELECT Replace(Val,' ','') as ReplaceColumn FROM CTE_REPLACE

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Regards, RSingh