A question about flattening instances upto stoplevel preseving vias?

Hi! All, I am using cadence IC514 version .. & .. tsmcN65nm PDK ..

In this PDK all vias are of type instances..

I am trying to flatten the entire cellview by preserving VIAs .. But I am in vain ..

Here is the code which will give an idea about what I am trying to do with ...

*************************************************

procedure(FLATTEN_INST()
foreach(inst deGetCellView()~>instances
       if(inst~>mosaic then
               leFlattenInst(inst~>mosaic 31 t nil nil)
       else
       if(!leIsAnyContact(inst)
               leFlattenInst(inst 31 t nil nil)
       )
       )
   )
);flatten_inst
*************************************************
The procedure FLATTEN_INST() has to flatten all instances upto stoplevel preserving VIAs ..

k1='()
procedure(inst_box(cv1 layer1 layer2 @optional (layer3 '("prBoundary" "drawing")))
l1=leLayerAnd(cv1 layer1 layer2 layer3)
foreach(box l1
       l2=dbGetTrueOverlaps(cv1 box~>bBox)
       foreach(ele l2
               if(leIsAnyContact(ele) then
               if(nth(0 area(ele~>bBox)) <= nth(0 area(box~>bBox))/2 || nth(1 area(ele~>bBox)) <= nth(1 area(box~>bBox))/2 then
                       ;geAddHilightRectangle(h1 box~>bBox )
                       k1=cons(box~>bBox k1)
               )
               )
       )
dbDeleteObject(box)
)
k1
)

inst_box(deGetEditCellView() '("M1" "drawing") '("M2" "drawing"))
inst_box(deGetEditCellView() '("M2" "drawing") '("M3" "drawing"))
......