The "By title and/or class" window mode is the correct choice because it is specifically designed to identify windows based on their title text. The "Window title" input field within this mode natively supports the use of wildcard characters, such as the asterisk () to represent any number of characters and the question mark (?) to represent a single character. This allows for flexible and dynamic window selection when the window title may change slightly, directly fulfilling the requirements of the scenario.

A. By window UI element: While a UI element's selector can be modified to use operators like "Contains" or regular expressions for dynamic matching, the "By title and/or class" mode is the most direct and intended method for using simple wildcards.
C. By window instance/handle: This mode identifies a specific, unique window that has already been captured and stored in a variable. It uses a direct reference, not a pattern with wildcards, for identification.
D. By variable: "By variable" is not a distinct window selection mode in Power Automate for desktop. While variables can be used to supply the title or handle within other modes, it is not a mode itself.

1. Microsoft Learn. (2023). Focus window. Power Automate Documentation.

Section: Parameters > Find window > By title and/or class > Window title.

Content: The documentation explicitly states for the "Window title" parameter: "The title of the window. Wildcard characters, that is, and ?, can be used." This directly supports option B as the correct method for using wildcards.

2. Microsoft Learn. (2023). Get window. Power Automate Documentation.

Section: Parameters > Get > Specific window.

Content: This documentation shows the same three selection modes: "By window UI element", "By title and/or class", and "By window instance/handle", confirming that "By variable" is not a valid mode. The "By window instance/handle" mode is shown to require a variable containing a window instance, which does not involve wildcard matching.

3. Microsoft Learn. (2023). Build custom selectors. Power Automate Documentation.

Section: Edit a selector > Operators.

Content: This document explains how to modify selectors for UI elements using different operators (e.g., "Starts with", "Contains") or by enabling "Use regular expressions". This confirms the mechanism for option A but highlights that it is a different approach from using simple wildcards directly in a title field.