change expression of radio button with update records

change expression of radio button with update records

I'm using a script in a subform so that when I change one field, the expression of a field in another form changes. I'm doing everything according to the instructions of ZOHO but nothing happens. The field I'm referring to is a radio button with 7 options. So the setting should change from one option to the other. 

Does anyone know if this is not possible? or if there's a workaround? 

The script I'm using is:
x = Nueva_Muestra[Lote == row.Numero_Lote];
x.Ubicacionlote="Trillado";

Nueva_Muestra is the form where the expression needs to be changed. 
Ubicacionlote is the field to be changed
Trillado is the setting the fields neds to be changed to.

Thanks