How to run a particular process

Hi I have a perl script where i created 3 nmap scans and the results will output to a text file. But when i run the code the first ip address gets scanned then the others after, but i want to be able to choose which ip address to scan.

Here is my code:

(`nmap -v -r 99.xxx.xxx -p 1-200>>99.txt`);
(`nmap -v -r 98.xxx.xxx -p 1-200>>98.txt`);
(`nmap -v -r 96.xxx.xxx -p 1-200>>96.txt`);

Is there anyone that can help me?