Does MOSS 2007 workflows support calling external mehods ?

Question

Hi all

I have a custom sharepoint workflow that I need to call an external method defined in a local service

it always throws an exception

System.InvalidOperationException: Could not find service of type 'ListItemCheckService.IListItemCheck' through the currently configured services. Consider adding the service to ExternalDataExchangeService.
    at System.Workflow.Activities.CallExternalMethodActivity.Execute(ActivityExecutionContext executionContext)
    at System.Workflow.ComponentModel.ActivityExecutor`1.Execute(T activity, ActivityExecutionContext executionContext)
    at System.Workflow.ComponentModel.ActivityExecutor`1.Execute(Activity activity, ActivityExecutionContext executionContext)
    at System.Workflow.ComponentModel.ActivityExecutorOperation.Run(IWorkflowCoreRuntime workflowCoreRuntime)
    at System.Workflow.Runtime.Scheduler.Run()

the question is does the sharepoint workflow system support calling external methods from a local service ?

thanks