Any activity in SysWOW64 should be included in the package automatically when it is built.
Using Package Editor under the Files tab, you could drag SysWOW64 directory to %System% folder to add the entire directory to your package. (Click Add empty folder icon and name it %System% if your package does not have %System% folder already.)
Depending on what your intention is, there may be a better way to accomplish what you are trying to do.
