>You can use a combination of DATEADD() and DATEDIFF() functions to perform what you are trying to do. Basically the code below calls the DATEDIFF function to return the time portion as the number of milliseconds, then calls the DATEADD function to add the number of millisec's to the date. This assumes that you always want to add the time portion from @settime to the @newdate variable and the time portion of @newdate is always 00:00:00.
>
>

>DECLARE @settime DATETIME,
>        @newdate DATETIME,
>        @result  DATETIME
>
>SELECT @settime = '1/1/1900 9:10:48 AM',
>       @newdate = '7/13/2005'
>
>
>SELECT @result = DATEADD(ms,DATEDIFF(ms,'01/01/1900',@settime),@newdate)
>PRINT @result
>

You'll get incorrect result for any other date. Try, for example,

SELECT @settime = '12/10/1999 9:10:48 AM'