exact text string patter test

[Dicken]

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. 

[lbendlin · Accepted solution]

You would want to check that you string has exactly 7 characters. Then you would only need to test for Text.Middle.

Word of advice: Power Query is case sensitive.

[Dicken]

yes i realised my mistake after postng.