possible :

1) take the tablespace offline
2) move the datafiles at OS level
3) alter tablespace xxx rename datafile 'olddatafile1' 'olddatafile2'
to 'newdatafile1' 'newdatafile2'
4) take the tablespace online

this works only with non system tablespace because u cannot take system tablespace offline

hope that will help

the other solution is startup nomount ur database and use
alter database move datafile ...