var inFormula = 'formulanumeric:'+ String("case when {name} in ('") + String(paramItems.join("','")) + String("') then 1 else 0 end");
var filters = [
	['isinactive',<http://search.Operator.IS|search.Operator.IS>,'F'], 'AND',
	[inFormula,search.Operator.GREATERTHAN,0]
];

error is because server side rhino engine doesn't think a string concatenation is a string needs some extra convincing wrap the final variable in String()