Static indication filters

Hello,

I'm writing a set of providers which have very limited indication
support. Therefore I want to provider only static set of indication
filters, which will cover all the indication my providers are able to serve.

Now the question is, how to make these filters visible to applications?
If I add instances to root/PG_Interop:CIM_IndicationFilter, anybody can
modify or delete them. But I'd like to have them read-only. I tried to
subclass CIM_IndicationFilter and create a provider which would provide
just these static filters, but then I am not able to create subscription
- it accepts only CIM_IndicationFilter as Filter property.

Is there any other way how to make my indication filters static, i.e.
read-only?

Thanks in advance

Jan