BPM input values manually

Is it possible to force a user to input values manually on a “Script Task” or any other way?

The idea is to use this value on a “Approved” task. My goal is to avoid beans-services which needs app updates and be able to create such BPM model directly on customer server.

A sample:
-User1 add a spending bill 23€.
-User1 Start approvement process to manager role User2
-User2 Approves the spending bill, allowing only 20€ (value to be saved on a hidden field)

Edit Screens who could be subject to some BPM process would already have included ProcActionsFrame and its initialization with predefined names (PROCESS_CODE).

Thanks in advance.

I suggest you to write your bpm-form with included “custom variable” field.
Doesn’t want to restart app every time new variable appear?
You can make it custom-generated. Here some sketch with form parameters:

<?xml version="1.0" encoding="UTF-8"?>
<forms xmlns="http://schemas.haulmont.com/cuba/bpm-forms.xsd">
    <form name="custom_var_bpm_form" default="false"><!-- input -->
        <param name="var_count"/> <!-- 3 -->
        <param name="var_ref"/> <!-- spend_bill;next_date;prev_date -->
		<param name="var_class"/> <!-- int;date;date -->
		<param name="var_local"/> <!-- Bill;Next bill date;Previos Bill date -->		

Depends on imagination. But basically i see it like good solution for your task.

Thanks for your answer. Will give it a try.