Oracle Query - Single Quotes and Characters

Hi all...

 

I have a variable -

PQUERY Varchar2(4000);

 

My QUERY is -

 

PQUERY  := PQUERY || 'select e.FName, e.LName, e.Age, e.Salary from Emp e where e. dtadded between to_date( 'Fromdate', 'dd-MON-yyyy') and to_date ('ToDate' , 'dd-MON-yyyy')'

 

Here -

 FromDate and ToDate are variables.

 

How to insert single quotes and characters in this string - Please help..