Forms :: Reg CSV File

The form which i developed is for Multiple user. i.e many no of user upload the same csv file at the same time. To differentiate it 4r the user i gave the user name in Prefix. say the users name are xx and yy and the file name is test.csv. In the kentucky server it is loaded as "xx_test.csv" and "yy_test.csv". It loaded along with Double quotes.I used the varible to get loaded

l_bare_filename := '"'||v_username||'_'||substr(:FIC_SOURCE,instr(:FIC_SOURCE,'',-1)+1)||'"';

l_bare_filename is that variable.

When i tried to null the csv file it is not created as Double quotes in Kentucky server. say it is displaying xx_test.csv file. Below is the command for making null. I used the same variable

host('cat /dev/null > /tmp/'||l_bare_filename )

I want it to be displayed with Double quotes.