Can you explain me how to add non-critical updates?

I read in this forum that is possible to manually add some non critical updates to static packages ... how exactly ?
I can be more exact: I've created the ISO on another PC. Now i've already Office 2010 ita + global update installer ISO.
I've seen some not-included updated availabl online.
I'd like to manually download it (i cannot redownload ALL from scratch and i've no more access to the pc) and then add directly to the (uncompressed) iso.
Then I'll be able to recreate a more-updated iso.
Is it possible ?
I can be more exact: I've created the ISO on another PC. Now i've already Office 2010 ita + global update installer ISO.
I've seen some not-included updated availabl online.
I'd like to manually download it (i cannot redownload ALL from scratch and i've no more access to the pc) and then add directly to the (uncompressed) iso.
Then I'll be able to recreate a more-updated iso.
Is it possible ?