To really help we will need the DDL (CREATE TABLE statement) for the table(s) involved, sample data (not production data) as INSERT VALUES statements for the table(s) involved, and based...

Does Unitrend have a utility program to create a native SQL Server backup file from their backup file?

The next question is this, what are attempting to accomplish?

If your data has 20 columns why is the header only 5 columns?

Just be careful converting...

Also, read the Microsoft documentation using the link I had posted (that is a link I would click on).

Give this a try:

DECLARE @theDate varchar(22)
        , @SQLCmd NVARCHAR(MAX);

SET @theDate = CONVERT(VARCHAR(22),CAST(CAST(dateadd(dd,-28,getdate()) AS DATE) AS DATETIME2),126)
SET @SQLCmd = N'
SELECT
  *,
  '''...