is there a way to use reset password with custom field?

where is compeelet list of this type of substitutions like this [post_checkemail] ?

There isn't. It comes from the HTML form POST data. Use your browsers developer tools (press F12) to observe network traffic to see what data is sent if you need a specific POST value.

only my problem is how to insert new input?

Act on the onLostPassForm trigger in CB Auto Actions using a Code action. Set Method to HTML then under Output be sure to return an array of label, input, and input name. Example as follows.

Global
Trigger: onLostPassForm
Type: Code
User: Automatic
Access: Everybody
Action
Method: HTML
Code: INPUT_HTML_HERE
Output
Display: return
Layout: Method: PHP

You'll still need to work out adding the necessary jQuery to allow the form to submit/validate, but the above will add an input to the forgot login form fine.

is it possible to get [post_checkemail] and edit it's value and then send to CB ?
i want stay between forgot login form and CB for edit [post_checkemail] value.

is it possible to get [post_checkemail] and edit it's value and then send to CB ?

The below triggers are a part of the forgot login process. You can explore using them however you like to figure out how to implement your custom forgot login solution.

Triggers directly at the top of the forgot login process before any action has taken place.
Triggers directly before the forgot username email is sent.
Triggers directly after the forgot username email is sent.
Triggers directly before password reset process begins.
Triggers directly before password is actually reset and before email.
Triggers after the password has reset and email has been sent.
All reference variables can be of course modified by reference in a Code action using PHP or in Output using PHP as long as you've specified them as references under the Parameters tab. For a list of triggers and their variables as shown above please read the below documentation carefully.

www.joomlapolis.com/documentation/279-community-builder/tutorials/18358-using-cb-triggers