Automate manual drag and drop code

Dear performers, please indicate the cost of work and the deadline for the execution, to save time.

Dano:
- two identical web pages
- both pages have a field for entering a code (password) by the visitor, the field is protected from attempts to insert the code copied in a third-party source with the right mouse button or Ctrl + V, but it is not protected from inserting code by dragging it from another window
Both pages have the same (but not the same) flaw in HTML code, which is manually fixed to achieve the desired effect.

The task is to automate manual drag and drop of copied code (password) and manual correction of html-code of the page, i.e. Develop a program or add-on in the browser that will allow:
- insert the copied code (password) into the protected field, simulating drag and drop
- fix the flaw in the html code on the necessary values in advance entered into the program

Desired interface: the operator opens the Internet page, opens the program / add-on, copies from an external source the code (password) in the program field, after which the operator presses a button in the program like "activate". After pressing the button, the program simulates dragging the entered code (password) into the desired field and changes the html code of the page. The operator does not have to see the processes, he is just a user whose task is to enter data.

The websites in question will be communicated to a specific performer. A mandatory requirement for the contractor is the presence of confirmed positive reviews and confidentiality.