[DmitriiV]

Например, так:

Код:

Dim objFS, objFile, arrData, arrTemp, strTemp
strPath = "D:\Temp\log.txt"
Set objFS = CreateObject("Scripting.FileSystemObject")
If objFS.FileExists(strPath) Then
    Set objFile = objFS.OpenTextFile(strPath, 1)
    arrData = Split(objFile.ReadAll, vbNewLine)
    objFile.Close
    For i = 0 To UBound(arrData)
        If Len(arrData(i)) > 0 Then
            If InStr(arrData(i), ":00") > 0 Then
                arrTemp = Split(arrData(i), ":00")
                strTemp = DateAdd("h", 4, arrTemp(0))
                arrData(i) = FormatDateTime(strTemp, 2) & " " & FormatDateTime(strTemp, 4) & ":00" & arrTemp(1)
            End If
        End If
    Next
    Set objFile = objFS.OpenTextFile(strPath, 2, True)
    For i = 0 To UBound(arrData)
        objFile.WriteLine arrData(i)
    Next
    Erase arrData
    objFile.Close
    Set objFile = Nothing
    WScript.Echo "Готово."
Else
    WScript.Echo "Не найден путь " & strPath
End If
Set objFS = Nothing
WScript.Quit 0