Currently when you run a TestPartner script through SCTM, the result file gets dynamically copied to a temporary Perfprojects folder (C:\Documents and Settings\\Local Settings\Temp\SCC_ExecServer_19124_19125\PerfProjects) on the Execution server machine.  Only files in this directory will get uploaded to the files tab of that execution run in SCTM.  See screenshot below:-

SCTM stores the path to the perfprojects directory in an environment variable called #sctm_test_results_dir.  You can amend your TestPartner script to save your text file to the "#sctm_test_results_dir" directory.  See sample script below:-

Option Explicit
Sub Main()
create_SCTMfile
End Sub

Sub create_SCTMfile()
   Dim sPath As String
   Dim sFname As String
   Dim i As Integer
  
   ' Reading and printing path of SCTM environment variable
   sPath = Environ("#sctm_test_results_dir")
   TestLog.Comment (sPath)
  
   ' Creating a text file and saving to above directory for SCTM to read back to files tab of execution run results
   sFname = "MyFile.txt"
   i = FreeFile
   Open sPath & "\" & sFname For Output As #i
   Write #i, "Writing a file to SCTM execution results" 'Entering test data in the text file
   Close

End Sub


MyFile.txt will then be uploaded to the files section in SCTM after the execution finishes:  See screenshot:-