Nothing from the valmet will fit.
Converting a type 81 to 223 would present the following problems:
barrel - easy - replace, put original hardware on the barrel.
bolt - hard - bolt face will need to have a ring welded on, new extractor made
magazines - this is the most complicated part - 223 ak pattern mags are harder to get than 7.62x39. If you were hoping to use stanag mags, you'll need to design and manufacture an adapter, because there isn't one available (maybe yet).
If you really want to get into it - try Heron Arms, but he'll be asking you the same questions above. Probably easiest to wait for Norinco to come out with a 223 version.