Hi

You need to just copy the datafile from the standby database to the server where you want the clone to be.

Just use the rman copy command to do this its very simple something like

RMAN> run{
backup as copy datafile 1 format 'D:\ORADATA\CLONEDB\SYSTEM01.DBF';
.....
}

take a backup of the controlfile to trace edit and to change the paths and then use it to recreate the controlfile on the clone database.

make sure you edit the first few lines to

create controlfile set database 'dbname' resetlogs

once the controlfile is created and the database mounted

recover datbase using backupcontrolfile until cancel

apply archivelogs if any to make it consistent and then open the database with alter database open resetlogs

hope you get the idea

regards
Hrishy