TCC Projection Function to find Position of Character

Summary

In an Export Projection, how can I find the position of a character in a string?

Content

In a TCC Export Projection, how do I find the position of a character in a string?  I'd like to use that value in Substring.

Example:

ExField: "Foo Bar (Hello) World"

Expected Results: "Foo Bar World"

<substring>

<field path="ExField"/>

<integer>

<instr path="ExField">

<string>(</string>

</instr>

</integer>

<integer>

<instr path="ExField">

<string>)</string>

</instr>

</integer>

</substring>