exact text string patter test

hi, i've been experimentin with regex patterns and wondered about replicating in power query, 
so this does seem to work, but can anyone suggest simpler / better way, so here i want to test for a pattern of 
any 2 characters,  then "abc"  then any two characters end.  
so regex ; 
=REGEXTEST("xxabcxx","^.{2}abc.{2}$",1)

in power qeuery i have;

let
  Source = #table(type table [sometext], {{"xxabcxx"}}),
  #"Added Custom" = Table.AddColumn(
    Source,
    "Custom",
    each
      let
        f = Text.Start([sometext], 2),
        e = Text.End([sometext], 2),
        m = Text.Middle([sometext], 2, 3)
      in
        f & m & e = [sometext]
  )
in
  #"Added Custom"

Richard.