Wildcards in “Not Spotter Callsign”

I’d like to be able to use wildcards in “Not Spotter Callsign”. I frequently see the following spotters N0CALL, N0CALL/M, NOCALL, NOCALL/M, NOCALL/N, NOOB4IK, which all resolve to USA, where I live, and are invalid USA call signs. I want to see spots from North America but I suspect these are not from NA. They change frequently and are a nuisance to keep up with. I’d like to be able to exclude them with, for example, “NOC*, *CALL”, etc.