This is an impossible question to answer without any knowledge about the test sequencer you are using or what kind of API the vendor is providing.
You are not saying if you want to do this from within a test method or by using an external application, for example for the purpose of automate some user interface tests.
If you want to do this from an external application, there are some options.
One way is to record mouse operations and play them as a macro. There are some softwares out there that has this functionality, but I have not used any such software in years so I can't recommend any good one.
Here is one web page a Google search came up with:
Record Mouse Clicks And Keystrokes[
^]
Another option is to use good old Spy++ and find out the ID's of the the different menu items and controls you need to manipulate.
Then you can use Win32 methods such as
SendMessage or
PostMessage in order to simulate mouse clicks.
In my experience this is easier if the UI is written in Win32 C++.
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