This command is undocumented in the original VFP9 help file,
but the following documentation was found in the FoxPro for Windows 2.6 help, and may still be valid:

Activates a menu bar.

Parameters

memvar
 The value initially contained in the memory variable or array element memvar specifies which menu pad is selected when the menu bar is activated. When you choose a menu pad, a value is stored to memvar corresponding to the menu pad you choose. If you press Esc to exit the menu, memvar contains 0.

Remarks

See Also