Passing variables from 1 plugin to another within an Authentication Module

Is there a standard way to pass plugin parameter values from a custom plugin to a standard plugin (in this case the UserIdentificationPlugin)?   In particular, I'm trying to dynamically populate the plugin parameter UserIdentificationPlugin.KEY_LDAP_FILTER from my custom plugin (which is upstream) . 

So in my plugin code, I'm trying to set the value in the plugin response like this:

  PluginResponse rsp = new PluginResponse();
  rsp.setName(PluginConstants.KEY_LDAP_FILTER);
  rsp.setKeyName(PluginConstants.KEY_LDAP_FILTER);
  rsp.setValue("(&(objectCategory=person)(objectClass=user)(samaccountname=someUserID))");
  rsp.setType(PluginAttributeContextType.LITERAL);
  context.addResponse(rsp);

Then in the UserIdentificationPlugin Step Details, I'm tring to set the value of the KEY_LDAP_FILTER parameter using syntax like this:  $KEY_LDAP_FILTER