It seems that it's impossible to declare an Alias like:

Alias=k.input:log[/var/log/program.log,"Starting to work on [0-9]+ orders"]

and use an active check (the server marks the item as unsupported with the following message: "Accessible only as active check")

whereas using log[/var/log/program.log,"Starting to work on [0-9]+ orders"] as an active agent check item on the server works as expected.

I have a few big regular expressions and I'd like them to be stored on the agent side.

Am I missing something? If not, then I think it's either a bug or it should be stated more explicitely in the documentation that aliases are not compatible with active agent checks.