Show custom message to specific lead

Is there a way, how to display a custom message to a specifig lead group?

For example, it will be great to be able to identify all non-anonymous returning leads from Europe and show them tailored message just for them.

I imagine that cookies will be utilised in this case. Something like:

if fromEurope == true

send:

    cookie.name = customContent

    cookie.value = europeMsg

else

send:

    cookie.name = customContent

    cookie.value = genericMsg

Then on our page, we will be able to run a script and show content based on the cookie value.

Thank you for your help.

send:

    cookie.name = customContent

    cookie.value = europeMsg