Add new column from complex SQL

To an existing sql result, I must add a new column. The new column is retrieved from a complex SQL

SQL result 1 (existing sql result)
==========================
select id, amount from MortgEdit1 where id = 1234

ID              Amount
1234      750.00


SQL result 2 (result of complex SQL)
=====================================
      DECLARE @Names VARCHAR(1000)
      
      SELECT
            @Names = COALESCE(@Names,'') + ciLastName + ',' + ciFirstName + ';'
      from
            mortgMaster
      inner join
            mortgdetail
      on
            mmid = mdmmId
      inner join
            contactinfo
      on
            mdidn = ciId
      where
            mdActive = 'Active' and
            mmActive = 'Active' and
            mdParentName = 'Applicants' and
            mmId = 12345

      
      SET @Names = Case @Names when null then null else (case LEN(@Names) when 0 then @Names else LEFT(@Names, LEN(@Names) - 1) end ) end
      SELECT @Names AS Names

Names
John; Carol; Jack


Result for which I am after
===========================
ID              AMount      Names
1234      750.00      John; Carol; Jack