File Rename with File System Task

I am using expression like below. How to remove the .7630000000? I need only Hrs,Min,Sec

@[User::SourcePath] +  (DT_WSTR, 100)  (DT_DBTIMESTAMP)  GETDATE() +   SUBSTRING( @[User::FileName], 

1,  FINDSTRING( @[User::FileName], ".", 1 ) ) + "xlsx"

U:\Reports\2013-06-13 23:02:20.736000000xlsx