Hi,
You can use wilcard patterns with regapp names in a selection filter.
[CommandMethod("Test")]
public void Test()
{
Document doc = Application.DocumentManager.MdiActiveDocument;
Editor ed = doc.Editor;
TypedValue[] filter = { new TypedValue(1001, "MyAppName*") };
PromptSelectionResult psr = ed.GetSelection(new SelectionFilter(filter));
if (psr.Status != PromptStatus.OK) return;
ed.SetImpliedSelection(psr.Value.GetObjectIds());
}