Excel regex link rewriter

uplink.cs

using System;
using System.IO;
using System.Text.RegularExpressions;
using Excel = Microsoft.Office.Interop.Excel;

class Guarded<T> : IDisposable {
    public Guarded(T val, Action<T> onDispose)
    {
        this.val = val;
        this.onDispose = onDispose;
    }

    public T Value {
        get { return val; }
    }

    public void Dispose()
    {
        onDispose(val);
    }

    private T val;
    private Action<T> onDispose;
}

static class UpLink {
    public static void rewriteLinks(Excel.Worksheet ws,
            string pat, string replace)
    {
        foreach (Excel.Hyperlink h in ws.Hyperlinks) {
            h.Address = Regex.Replace(h.Address, pat, replace);
        }
    }

    public static void Main(string[] args)
    {
        if (args.Length != 3)
        {
            Console.Error.WriteLine(
                    "Usage: uplink workbook-path find-pattern replace-pattern");
            return;
        }

        var wbPath = Path.GetFullPath(args[0]);

        using (var xl = new Guarded<Excel.Application>(
                    new Excel.Application(),
                    xl => xl.Quit())) {
            using (var wb = new Guarded<Excel.Workbook>(
                        xl.Value.Workbooks.Open(wbPath),
                        wb => wb.Close(false))) {
                foreach (Excel.Worksheet ws in wb.Value.Worksheets) {
                    rewriteLinks(ws, args[1], args[2]);
                }
                wb.Value.Save();
            }
        }
    }
}