VBSの質問です

Const InFolder = "ああ"
Const OutFileName = "ketugo.html"
Const ForReading = 1, ForWriting = 2
Dim fso, f, fc, fn, InFile, OutFile
Set fso = WScript.CreateObject("Scripting.FileSystemObject")
Set objWshShell = WScript.CreateObject("WScript.Shell")
Set RE = CreateObject("VBScript.RegExp")

RE.Pattern = InFolder & "*"
strPATH = Wscript.ScriptFullName
InFolder2 = Left(strPATH,InStrRev(strPATH,"\")-1)

Set f = fso.GetFolder(InFolder2)

Set fc = f.Files


Set OutFile = fso.OpenTextFile(OutFileName, ForWriting, true)
For Each fn in fc
	If right(fn.name,5)=".html" and  RE.Test(fn.name) and len(fn.name) = len(InFolder)+6 then
		c= mid(fn.name,len(InFolder)+1,1)
		if c>="0" and c<="9" then
			Set InFile = fso.OpenTextFile(fn, ForReading)
			OutFile.Write(InFile.ReadAll())
			InFile.Close()
		end if
	end if
Next
OutFile.Close()
Set fso = Nothing
Set RE = Nothing

けっこう修正しないと ちゃんと動きませんでした。

これまでにも利用してきたRegExpを使った例

Const InFolder = "ああ.html"
Const OutFileName = "ketugo.html"
Const ForReading = 1, ForWriting = 2
Dim fso, f, fc, fn, InFile, OutFile

Set fso = WScript.CreateObject("Scripting.FileSystemObject")
Set f = fso.GetFolder(InFolder)
Set fc = f.Files
Set OutFile = fso.OpenTextFile(OutFileName, ForWriting, true)

Set objEXP = New RegExp
objEXP.Pattern = "^ああ[0-9]\.html$"

For Each fn in fc
    If objEXP.Test(fn.Name) THEN
        Set InFile = fso.OpenTextFile(fn, ForReading)
        OutFile.Write(InFile.ReadAll())
        InFile.Close()
    End If
Next

元のソースに加えたのは下記２点です。

' パターン検索の準備
Set objEXP = New RegExp
objEXP.Pattern = "^ああ[0-9]\.html$"

' 下記の設定はデフォルトがFALSEなので今回は省きました。
objEXP.Multiline = False
objEXP.Global = False

' パターン適合性のテスト
    If objEXP.Test(fn.Name) THEN
    End If