/Set-ProvisionedAppxDataFile /CustomDataPath: /PackageName: Use /CustomDataPath to specify the custom data for the app package ...

/Set-ProvisionedAppxDataFile /CustomDataPath: 
  /PackageName:
  Use /CustomDataPath to specify the custom data for the app package (.appx 
  or .appxbundle). 
  Use /PackageName to specify the Package Full Name of the app package 
  (.appx or .appxbundle) to modify. 

    Example:
      DISM.exe /Image:C:	est\offline /Set-ProvisionedAppxDataFile 
        /CustomDataPath:c:	est\Apps\Custom.dat 
        /PackageName:microsoft.appx.app1_1.0.0.0_neutral_en-us_ac4zc6fex2zjp