In case you mean the sample script in Applications/Samples/[Insert Programming Language]/PlaceMultipagePDF: What is your question?
1. "The script does not ask for these values". That seems to be correct. It does not, and never did. So it is working as intended.
2. "We want to enhance the script and add this functionality but we are unable to do so ..."
2a. ".. because we cannot find the proper commands to insert." Placing PDFs has been asked before (many times), search this forum for tips.
2b. ".. because we cannot write scripts, plz do the useful". That is not what this forum is for.
Way more likely is that you are confusing Adobe's example script with the much more powerful MultiPageImporter by Scott Zanelli (http://indesignsecrets.com/zanelli-releases-multipageimporter-for-importing-both-pdf-and-i ndd-files.php).