I want to use the SDO_CS.TRANSFORM function to transformate table-coordinates from one coordinate system into another?

I have a table called MAPS containing coordinates in two different coordinate systems. I want to create a trigger, which updates the second coordinate system, when changes are made in the first.

Example:
create table MAPS (MSLINK number, x_s34 number, y_s34 number, x_utm number, y_utm number);

insert into MAPS (mslink,x_s34,y_s34) values (1, 123,234);
insert into MAPS (mslink,x_utm,y_utm) values (2, 543,432);

The two coordinate systems are given in the mdsys.cs_srs table as
SRID=278528 and SRID=82344

What I need now is a syntax like

select
SDO_CS.TRANSFORM(278528,82344,x_s34,y_s34,0)
from
all_maps
where
mslink = 1;

Which should give me the coordinates in x_utm, y_utm, z (null).

Is that possible at all?