Rick
In order to get the text box to appear in the calc network, you need to take a look at the extender properties that the UltraCalcManager adds to the various controls and fill in the fields that will provide enough information for the manager to pull the value. For example, on my UltraTextEditor, I assigned an Alias of "Search", the PropertyName of "Text", and the TreatAsType to "System.String", so my control will appear in the Formula Builder is "Search.Text" and is references in formulas by "[//Search]".
-Matt