Designer 10.7 | webMethods Service Development Help | Regular Expressions | Using a Regular Expression in a Mask
 
Using a Regular Expression in a Mask
When you use a regular expression as a mask, you use parentheses to specify which characters you want to collect. For example, the object reference:
doc.p[].text[/(.{30}).*/]
retains the first 30 characters in each matching element and discards the rest.