PACtool update "1.3", requires VC++ redist 2013.
This is 100% of IndigoDesert's code, this simply disables the statement that results the error "Bone count in DAE doesn't match the one in PAC! Adding new bones isn't supported yet.", hasn't been fully tested but as far as I can tell support for adding new bones was added and this statement was never removed.
This will allow binding meshes to more bones, even if the bones weren't originally in use by the mesh, as long as the bones exist in the provided PAB file.