You can determine whether the grid is in edit mode by reading the value of the EditWindow property. If this property returns zero, the grid is not in edit mode. If it returns a non-zero value, the grid is in edit mode and the value returned is the handle of the edit window.
You can force the grid into edit mode at any time using the EditCell method. You can even allow the user to edit fixed cells by selecting them in code (using the Select method) and then invoking the EditCell method. You can cancel the edit mode by selecting the current cell (for example, .Select .Row, .Col).