Office Plug-In: Disable "Save" button at run time

Dear all,

I'm developing Office Plugin for MS Office 2010 and 2013. 

I'm looking for solution how to control disable/enable menu button such as "SAVE", "SAVE AS", "PRINT" or "Prepare" at run time. Form now I only disable these controls by using setting Ribbon  XML, and cannot enable at run time, for example 

<customUI onLoad="Ribbon_Load">

  <commands>

    <commandidMso="FileDocumentEncrypt"enabled="false"/>

      </commands>

</customUI>

So does anyone can suggest me other solution? 

Thank you!

Best regards

Johnny