Hi Kavitha ,
Please follow below Steps.
Run Tcode : NACE
Click on Highlighted Entry and click on Output Types :
Select Output type and Double click on Processing Routines.
Now Here you have 2 options. 1st is either copy your standard Report into Z Report and Customize it and write code to call your Z smartform to use to your Z Smartform as mentioned below.
Click on change button on top and assign your custom Program and Custom Form Here.If you are using Smartform assign it in PDF/Smartform Form Tab.
Or Use Z Script in case if you don't want to change Standard Program as below.
In Script you can use all global parameters of SAPFM06P program to print the O/P.
If you use Smartform than You have to explicitly call this smartform with global parameters.So it is better we copy standard program into Z, and call your custom Z smartform in that program.
Hope this make sense.
Regards,
Sagar