[Iska]

Sally88, например, так:

Код:

Option Explicit

Const ForReading   = 1
Const ForWriting   = 2


Dim strFile

Dim strFind
Dim strFindPlus

Dim objFSO
Dim objRegExp

Dim strContent

strFile = "E:\Песочница\0099\text.txt"

strFind     = "строчка"
strFindPlus = "1" & strFind

With WScript.CreateObject("Scripting.FileSystemObject")
	If .FileExists(strFile) Then
		Set objRegExp = WScript.CreateObject("VBScript.RegExp")
		
		With objRegExp
			.IgnoreCase = True
			.Global     = True
			.Pattern    = strFindPlus
		End With
		
		With .OpenTextFile(strFile, ForReading)
			strContent = .ReadAll()
			
			.Close
		End With
		
		With .OpenTextFile(strFile, ForWriting)
			If objRegExp.Test(strContent) Then
				.Write objRegExp.Replace(strContent, strFind)
			Else
				objRegExp.Pattern = strFind
				.Write objRegExp.Replace(strContent, strFindPlus)
			End If
			
			.Close
		End With
		
		Set objRegExp = Nothing
	Else
		WScript.Echo "File [" & strFile & "] not found"
	End If
End With

WScript.Quit 0