Handle Password Input?

Is there a way to type in a cell and click on a Command Button instead of the Enter Key-- and then run a macro using the value that was typed into that cell? Or any other way to eliminate the need to hit Enter Key to record the user input and then hit Command Button to run the macro? I have 40+ users who login in by selecting their name from a drop down list and then entering their password in another cell. (what they input must match another cell in same row.) Attached is scaled down model of Workbook and the macro that works to login.