Match string format with regex : <p>I know there are tons of questions about regex string format, but I am very new to this and I haven't been able to do it myself. How can I use regex to match a string with the following format?</p>

<p><code>xx_x_a.zip</code></p>

<p>where x is a number and a is a letter. Example:</p>

<p><code>33_2_f.zip</code></p>

<p>It must not match:</p>

<p><code>33_2_f_abc.zip</code></p>

<p>The format must always be like <code>2digits</code>+<code>_</code>+<code>1digit</code>+<code>_</code>+<code>1letter</code>+<code>.zip</code></p>
