This is a common request of ex-Windows Keyboard Maestro users. Apparently there is a window key which will display a contextual menu based on the insertion point, but there is no equivalent behaviour on the Mac. It is impossible in general to get the screen location of the current insertion point (some applications may allow some method via AppleScript or Assistive services).
So there is no way to move the mouse pointer to the insertion location in general, and the contextual menus are based on the mouse pointer.
This is why Keyboard Maestro doesn't implement this, and without some low level hackery, it is almost certainly impossible.
So essentially you are out of luck. You will need to find an alternative solution to your issue.
Cmd-?to open Help menu's search field and type your command instead, or useCtrl-F2to move the focus to the menu bar and navigate to your desired action there. Or better, assign keyboard shortcuts to often used commands in System Preferences » Keyboard » Keyboard Shortcuts » Applications so you can access them directly. – Daniel Beck♦ Mar 2 '11 at 6:44