symmetry modifer acting on chusen polygon sub-objects

[vardanhn]

I would like 

to have option, for symmetry modifer

to mirror only spesific sub-ojvects

this is usfool whan you have a model

which have as symmetrical parts, and as non-symmetricla part

after I will symmetry-mirror model

I can match non-symmetry vertisic to symmetry bounderis

[vardanhn]

i found mirror modifier us working likewize way