Using AMPScript to define which Send Classification to use

OK, so I find myself in a Marketing Cloud environment where Send Classifications are set up individually for Denmark, Sweden, Germany, Schwitzerland and The Netherlands, but my new, triggered mail is built to dynamically show content based on the [Country Code] in the trigger data extension.

All 5 Send Classifications have external keys, can I assign a Send Classification inside the mail in AMPScript using the external key?

The following needs a rewrite, but hopes this makes what I wish for easy to understand:

<!--Script Blok-->%%[ /* Script Blok <div style="display:none"> */VAR @dyncountry SET @dyncountry = UPPERCASE([Country Code]) IF @dyncountry == "DK" THEN "Use Send Classification with External Key XXXX"ELSEIF @dyncountry == "CH" THEN ...and so on/*</div>*/]%%