$line =~ s/(SUM.*)(..)/$1/

should meet your requirement.

Bonus: $2 will hold the truncated characters.

Demo in the debugger 

  DB<1> $_ = 'abcSUMcdexx'

  DB<2> s/(SUM.*)(..)/$1/

  DB<3> p
abcSUMcde
  DB<3> $_ = 'abcSUXcdexx'

  DB<4> s/(SUM.*)(..)/$1/

  DB<5> p
abcSUXcdexx
  DB<5>

[download]

Update: typo fixed in DB<1> , thx to AnomalousMonk for spotting.

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery

In reply to Re: Trim Two Characters On Line by LanX
in thread Trim Two Characters On Line by jalopez453

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