>>STORE "Store" TO ("_screen." + "Caption")
>>= ADDPROPERTY(_screen, "Caption", "AddProperty")
>>_vfp.SetVar("_screen.Caption", "_vfp.setvar")
>
>addproperty is not good.
>it work with a missed property.

Said so myself in direct answer to Albert - but might actually be a benefit here, as it guarantees the property after the call to set it in both cases.
But _vfp.SetVar does NOT work on my machine with object.property, only with memvars:
_vfp.SetVar("m.myvar", "_vfp.setvar")
_vfp.SetVar("myvar2", "_vfp.setvar")