How do I use an expression in the 'Calculation' function to 'Extract Data' from a previous question in Survey123 web designer

[Matt-Goodman]

Hi, 

I can't decipher from any documentation how I'm supposed to build an expression to automatically calculate a value based on a previous question, specifically using the "String" option. Is this window expecting Arcade? When I write a basic expression, it get a syntax error. 

Arcade expression syntax error

I am hoping to use this function to parse off just the address number (1234) from the full address (1234 Maple Lane) in a previous question. 

[DuncanC]

I'd recommend using Survey123 Connect not the web designer.  Nobody uses the web designer, it only works for the simplest of forms.