C:\>perl -we "print ( split '_' , $myString )[1]"
print (...) interpreted as function at -e line 1.
syntax error at -e line 1, near ")["
Execution of -e aborted due to compilation errors.

##</code><code>##

C:\>perl -we "$myString = '123_456'; print( ( split '_' , $myString )[1] )"
456

##</code><code>##

C:\>perl -we "$myString = '123_456'; print( ( split /_/ , $myString )[1] )"
456