Keep sheet names unchanged after saving them as txt files.

[aadpors]

I want two sheets of my Excel workbook to be saved as txt file. The name of the file is compiled of a fixed part ("TrialList" or "BlockList") and two values from another sheet (subject and session number):

    Sheets("TrialList").Select
    Dim part1 As String
    Dim part2 As String
        part1 = Range("O2").Value 'subject number
        part2 = Range("P2").Value 'session number
    Sheets("txt").Select
    Cells.Select
    ActiveWorkbook.SaveAs Filename:= _
        "C:\...\TrialList " & part1 & "-" & part2 & ".txt", FileFormat:= _
        xlText, CreateBackup:=False
    Sheets("BlockList").Select
    Cells.Select
    ActiveWorkbook.SaveAs Filename:= _
        "C:\...\BlockList " & part1 & "-" & part2 & ".txt", FileFormat:= _
        xlText, CreateBackup:=False

Now, saving the text files with the desired file names works perfectly. However, Excel decides to change the names of the sheets that have been saved as text files accordingly. This is something I want to prevent from happening, since a second loop of actions will end because of the unexpected sheet names... How do I work around this autonomous behaviour of Excel?