was How To Modify Dynamic Browse Column Attributes

You can adjust the format of a column in the row-display trigger.

CREATE BROWSE hBrowse
    ASSIGN
    X = 17
    Y = 63
    WIDTH = 90
    DOWN = 14
    FRAME = FRAME {&frame-name}:handle
    READ-ONLY  = YES
    SENSITIVE = TRUE
    ROW-MARKERS = TRUE
    SEPARATORS = TRUE
    FIT-LAST-COLUMN = TRUE
    FONT = 1
    TRIGGERS:
        ON DEFAULT-ACTION
            DO:
                IF AVAILABLE(ttClienteNombre) THEN
                DO:
                    ASSIGN
                        pSeleccion = ttClienteNombre.cliente.
                    APPLY "GO":U TO FRAME {&FRAME-NAME}.
                END.
            END.
        ON ROW-DISPLAY
            DO:
                hColumn = hBrowse:GET-BROWSE-COLUMN(1).
                hColumn:FORMAT = "X(40)".
                hBrowse:GET-BROWSE-COLUMN(2):FORMAT = "X(15)".
                hBrowse:GET-BROWSE-COLUMN(2):FORMAT = "X(16)".
            END.
    END TRIGGERS.


CREATE QUERY hQuery.
hQuery:SET-BUFFERS(BUFFER ttClienteNombre:handle).

hQuery:QUERY-PREPARE(cBaseQuery).

hQuery:QUERY-OPEN ().

hBrowse:QUERY = hQuery.

hColumn = hBrowse:ADD-LIKE-COLUMN ("ttClienteNombre.Nombre").
hColumn = hBrowse:ADD-LIKE-COLUMN ("ttClienteNombre.RFC").
hColumn = hBrowse:ADD-LIKE-COLUMN ("ttClienteNombre.Cliente").
hBrowse:GET-BROWSE-COLUMN(1):Width = 35.
hBrowse:GET-BROWSE-COLUMN(2):Width = 15.
hBrowse:GET-BROWSE-COLUMN(3):Width = 10.

This is it.... to no avail.    It chaged column-with, but not format as names (Nombr) is truncated on display.

I believe you have to change the format of the field (rather than the browse's column) before the column is dynamically added to the browse (using ADD-LIKE-COLUMN).

Something like:

ASSIGN BUFFER ttClientNombre:BUFFER-FIELD("RFC"):FORMAT = "X(15)"
       BUFFER ttClientNombre:BUFFER-FIELD("Cliente"):FORMAT = "X(16)".