VBScript to loop through all files in a folder

Your current script basically does the following:

Set objFile = objFSO.OpenTextFile("...", ForReading)
Do Until objFile.AtEndOfStream
  strLine = objFile.ReadLine
  'do stuff with strLine and append to strText
Loop
objFile.Close

Set objFile = objFSO.OpenTextFile("...", ForWriting)
objFile.Write strText
objFile.Close

For processing all files in a given folder you just need to add an outer loop around that, and adjust some instructions accordingly:

For Each f In objFSO.GetFolder("C:\some\folder").Files
  Set objFile = f.OpenAsTextStream
  Do Until objFile.AtEndOfStream
    strLine = objFile.ReadLine
    'do stuff with strLine and append to strText
  Loop
  objFile.Close

  Set objFile = f.OpenAsTextStream(ForWriting)
  objFile.Write strText
  objFile.Close
Next

What would be even better is to do a recursive function to go into all folders that are below your main folder and search those as well.. Just and idea :)

Maybe this will clear things up. (Or confuse you more, )

Const ForReading = 1
Const ForWriting = 2

sFolder = "H:\Letter Display\Letters\"
Set oFSO = CreateObject("Scripting.FileSystemObject")

For Each oFile In oFSO.GetFolder(sFolder).Files
  If UCase(oFSO.GetExtensionName(oFile.Name)) = "LTR" Then
    ProcessFiles oFSO, oFile
  End if
Next

Set oFSO = Nothing


Sub ProcessFiles(FSO, File)

Set oFile2 = FSO.OpenTextFile(File.path, ForReading)

 str1000 = "1000"
 str1100 = "1100"
 str1200 = "1200"
 str9990 = "9990"

 arrCommas1 = Array(14,31,41,59,70,81,101,111,124,138)
 arrCommas2 = Array(14,31,41,55,79,144,209,274,409,563,589,608,623)
 arrCommas3 = ArraY  (14,32,41,73,83,97,106,156,167,184,188,195,207,260,273,332,368,431,461,472,593,617,666,772,810,834,848,894,898)
 arrCommas4 = Array(14,31,41)

     Do Until oFile2.AtEndOfStream
       strLine = oFile2.ReadLine

       If Left(strLine, 4) = str1000 then
         intLength = Len(strLine)
         For Each strComma in arrCommas1
           strLine = Left(strLine, strComma - 1) + "," _
             + Mid(strLine, strComma, intLength)
         Next
       End If

       If Left(strLine, 4) = str1100 then
         intLength = Len(strLine)
         For Each strComma in arrCommas2
           strLine = Left(strLine, strComma - 1) + "," _
             + Mid(strLine, strComma, intLength)
         Next
       End If

      If Left(strLine, 4) = str1200 then
         intLength = Len(strLine)
         For Each strComma in arrCommas3
           strLine = Left(strLine, strComma - 1) + "," _
             + Mid(strLine, strComma, intLength)
         Next
       End If

      If Left(strLine, 4) = str9990 then
         intLength = Len(strLine)
         For Each strComma in arrCommas4
           strLine = Left(strLine, strComma - 1) + "," _
             + Mid(strLine, strComma, intLength)
         Next
       End If

       strText = strText & strLine & vbCrLf
     Loop

     sFile = File.path
     oFile2.close
     set oFile2 = Nothing

     Set File = FSO.OpenTextFile(sFile ,  ForWriting)
     File.Write strText
     File.Close
     Set File = Nothing

 end sub