Standard way to define expressions in .NET application's UI?
<p>Perhaps somebody has <em>the</em> answer to the following conceptual question:</p>

<p>I am writing a (relatively trivial) application which takes records from a table (every line is a record, the colums are the fields), processes the records, and then writes the new records to a new table.</p>

<p>The problem is that the specification (i.e. how the output records look like and how they are computed) will change all the time and that the users do not have much experience with programming.</p>

<p>I would like to make the application configurable in the UI, i.e. I would like to enable the users to specify expressions like</p>

<pre><code>x * y - 3
</code></pre>

<p>or</p>

<pre><code>z.Substring (2)
</code></pre>

<p>somewhere in the UI (similar to Excel, where you can give formulas for cells).</p>

<p>Question: What is the best language for specifying simple mathematical, boolean, and string expressions?</p>

<p>I have considered the following:</p>

<ul>
<li>allow the users to enter PowerShell code</li>
<li>allow the users to enter C# code</li>
<li>writing a parser myself</li>
</ul>

<p>But all that seems to me extremely complicated. Do you have a better idea?</p>
