Backup directly to tape...?

Hi,

I wnet to take backup of a datafile and send directly to tape. Can any one guide me thru the command for this.

Now I am using below command
host cp /oradata01/PINFR040/BCPREHEARSAL_DATA01.01.dbf $HOTBKUP/oradata01/BCPREHEARSAL_DATA01.01.dbf

which will copy file to file s/m. Since file s/m size is less, I dont want to copy into file s/m instead copy directly to tape. Please guide me thru command to do this task.

Normaly we are using dsmc command to backup a file to tape. But how to use this at the time of copy itself..?

Regards,
tmg