How to fill an array into parameter?

Is it possible to fill an array into filter parameter some way?
I mean an equivalent of IN clause.
Something like AS:LookupValue (‘Id’, ‘par1’, [‘value1’, ‘value2’, …])

I have looked into AS:LookupValue() function and it’s not possible to pass parameter arrays into that function. But passing arrays into ‘IN’ filters is generally possible. Please can you describe your use case so that it’s more clear whether you really need it or it can be solved more elegant way differently?

I need to generate a number row on base of multiple referenced list items (in XSLT transformation).
Something like: search for max value in items where refTypeId = Value1 or Value2 (but not Value3) and generate something.
I can workaroud it quite easily, but IN construction would be much more handsome.

You can use IN and pass an indefinite number of parameters using AS:LookupValueEx function (currently undocumented), but your entity filter would have to contain a fixed number of parameters, e.g. Param1, Param2, Param3… ParamN so it would not be exactly an array of parameters but a long but limited list of parameters (but more than 3 which is the max LookupValue function allows).