title: translating filename wildcards to regex
body: <p>I need to translate arbitrary good old DOS wildcard strings to regex strings, which then are to be used with <code>System.Text.RegularExpressions.Regex</code>. Unfortunately, my regex knowledge is quite embarrassing. </p>
  
  <p>I'm trying to wrap my head around stuff like <code>*.*</code>, <code>.*</code>, and <code>*.</code>. My current problem is that <code>*.</code> is generally expected to match files that either end with a dot or have no dot at all.<br>
  So I translate <code>*.</code> into <code>^.+[^\.].*$</code>, but this is apparently wrong. It not only matches <code>blah</code> and <code>blah.</code>, but also <code>blah.blah</code>. </p>
  
  <p>So what's the correct regex syntax to match <code>blah</code> and <code>blah.</code>, but not <code>blah.blah</code>?</p>