Filter for selecting lines beginning/ending with characters

[gmb1994]

How do we select (extract) lines beginning with (or, ending with) a specific character (letter, digit, symbol, etc.) or sequence of characters, for example:

+ select lines beginning/ending with the letter 'a'
+ select lines beginning/ending with 'abc'
+ select lines beginning/ending with '$*3abc'

[DataMystic Support]

select lines beginning/ending with the letter 'a'

^a
/
a$

select lines beginning/ending with 'abc'

^abc
/
abc$

select lines beginning/ending with '$*3abc'

^\$\*3abc
/
\$\*3abc$