Command equivalent Sed in powershell ! please

Hello everyone,

I make a shell script to extract a figure on.

Here's an example where I seek to get the figure:

S-1-5-21-2266954777-2911002515-1883294743

result:

PS C: \ Users \ HACKMED \ Searches \ Pictures \ Documents \ script> whoami / ALL

User Information
------------------------

Username SID
================== ================================ ==============
hackmed-pc \ hackmed S-1-5-21-2266954777-2911002515-1883294743-1000

thank you

thank you