Select Features, custom featureset relating to features in the map

Hi.

Is it possible to build a custom featureset (original featureset plus some additional attributes) and make this featureset select the features in the map using "Select Features"?

I managed having the workflow collect features from 2 different featuresets and select those in the map (An example Ryan presented in another topic), but for other reasons I have to rearrange the featureset and now the featureset doesn't select the features.

Is it the OBJECTID or? And if, is there a way to tell that it is type OID, right now it is a string in my workflow?

René