Replacing LIKE with REGEX doubts

[Stan Busk]

Hi,

Just wondering some of the Valentina v1 LIKE equivalents using v2  
REGEX of

     Is equal to: myField LIKE '\Amytext\Z' no_case
Is not equal to: myField NOT LIKE '\Amytext\Z' no_case
        Contains: myField LIKE 'mytext' no_case
Doesn't contain: myField NOT LIKE 'mytext' no_case
     Starts with: myField LIKE '\Amytext' no_case
       Ends with: myField LIKE 'mytext\Z' no_case


are they?:


     Is equal to: myField REGEX '(?i)mytext'
Is not equal to: ???
        Contains: myField REGEX '(?i)[a-zA-Z0-9]+mytext[a-zA-Z0-9]+'
Doesn't contain: ???
     Starts with: myField REGEX '(?i)[a-zA-Z0-9]+mytext'
       Ends with: myField REGEX '(?i)mytext[a-zA-Z0-9]+'

If I am right with [a-zA-Z0-9]+ is there something better and wider?  
I mean that could consider more possible characters?

TIA,
~/Stan