Unfortunately, there is no function that will return the number of rows/records in the Table Window.
To work around this issue:
Create a Summary.
In addition to the fields listed, bring the "count" field in with the rest of your Measure fields.
In the General tab of the Summary Definition, change the Label: "Summary" to something unique from the first position of the first field. A Numeric value should work if your data begins with an Alpha Character, an Alpha Character if the data begins with a Numeric.
Export from the Summary creating a Fixed Width Text file (in the OptionsExport and....do not include the Field Headers as the first row of output).
Bring the new file into Monarch and build a Model that will extract the Field Data as Detail (trap using an Ã or Ñ in the first position), define the fields. And extract the last line containing your unique Label: ? as a Footer (trap using the reverse as above in the first position). Define the new field.
No matter the number of rows/records in the file, the second model will create a field that contains the correct number.
I hope this is helpful,
Datawatch Technical Support