Update substring of Text Box Value

Is there any native function to replace a substring within a text box?
In the example below i just want to change the word curious to the word simple without having to worry about its formatting, preserving what is currently set:
TextBox1 = This is a curious replacement of a substring without having to worry about potentially changing the formatting
Desired Result= This is a simple replacement of a substring without having to worry about potentially changing the formatting

Only thing that I am seeing is a full replace, might I be missing/overlooking something in the API?

Thanks

@jeffrlynch,
You can find a substring in the text of shape, and then replace it with the new string. Please refer to this help topic: Find and Replace the Text of a Shape

Thanks that example was just what i needed, thanks