Juan,
Field1, Field2...FieldX are exemplary field names, you must replace them with actual field names from the cursor (or table Proyecto). Also I see I have a typo thisfirm must be thisform.
Try:

Select * from proyecto ;
      where tipomed = m.type_p and numero = m.numero ;
Into cursor ResultSet
BROWSE NORMAL
thisform.text1.Value = EVALUATE("ResultSet."+Fields(1,"ResultSet"))

>""If you just want to store the values of the fields in textboxes:
>
>Select * from proyecto ;
> where tipomed = m.type_p and numero = m.numero ;
>Into cursor ResultSet
>
>thisfirm.text1.Value = ResultSet.Field1
>thisfirm.text2.Value = ResultSet.Field2
>etc.
>Is that what you want?""
>
>well...
>
>when i use I get this error:
>
>Variable 'FIELD1' is not found
>Variable 'FIELD2' is not found
>Alias 'RESULTSET' is not found
>
>:(