Use $eval(%setme1,2)
//var -s %number = 22,%22 = blah | set -s %setme1 $+(%,%number) | echo -a $eval(%setme1,2)
Keep in mind that if the variable %22 has no value, then $eval(%setme1,2)
will return $null, so for this example I gave the variable %22 the value of
blah.