try something like that:
Sub exportar_objectos_por_Capa()
arrFileExtnsions =Array(_
"3dm", "3ds" , "ai" , "pdf",_
"eps", "iges" , "dgn" , "fbx",_
"obj", "csv" , "skp" , "dxf",_
"slc", "sldprt", "step" , "stl",_
"svg", "vrml" , "zpr")
filename=Mid( Rhino.DocumentName (),1,InStrRev (Rhino.DocumentName (),".")-1 )
set fs=CreateObject("Scripting.FileSystemObject")
WF = fs.BuildPath(Rhino.DocumentPath (),"\Capas")
if NOT fs.FolderExists (wf) then
set WorkingFolder=fs.CreateFolder( wf)
ELSE
set WorkingFolder=fs.GetFolder( wf)
END IF
Rhino.WorkingFolder(WorkingFolder.Path)
extension=Rhino.ComboListBox (arrFileExtnsions,"Choose a file type, or write a Rhino supported format","Save objects selected by layer")
If IsNull(extension) then rhino.print "Nada seleccionado. Cancelado":exit sub
extension="."& extension
arrLayers = Rhino.LayerNames()
for each strLayer in arrLayers
arrObjects =Rhino.ObjectsByLayer (strLayer ,vbTrue)
If IsArray(arrObjects) then
strFilename=filename & "- (Capa ›› " & Replace(strLayer,"::",", Subcapa ›› ") & ")" & extension
rhino.print rhino.command ("_-export "& Chr(34) & strFilename & Chr(34) &" _EnterEnd", vbFalse)
Rhino.UnselectAllObjects ()
end If
next
End Sub