comment out a cron job as part of a script

Greetings,
I am creating a ksh script to automate the installation of a utility on many servers.
As part of this install, I want to check for a job in root's crontab.
If the job exists, I need to comment it out.
I know I will need to copy off the crontab then read it back in, but I am struggling on commenting the job out while maintaining the integrity of the crontab.
The job will have the same path, so this is a constant to check for.
The crontab entry might not reside on the same line for each server.
Any tips would be appreciated.
Thanks

You can copy off the crontab, grep for the job name, if found, put a hash at the beginning of the line (you can use sed) and write it back.

Show us the code you have tried so far.

I am aware of all those steps. It is the syntax of the sed command that I am struggling with. If I just grep for the command and issue the

sed 's/^/#/'
#0 10 * * 5 /my/cron/job 

I only get that single line in my new file. I am not strong with sed and need some help with the [address]. I have tried these and get the same error,

$ crontab -l | sed [/my/cron/job]s/^/#/
Unrecognized command: [/my/cron/job]s/^/#/
$ crontab -l | sed '[/my/cron/job]s/^/#/'
Unrecognized command: [/my/cron/job]s/^/#/

Thats why you should start with posting code to save everyone's time. Here goes:

$ cat cron.sample
0 10 * * 5 /my/cron/job
0 10 * * 5 /other/cron/job

$ cat cron.sample |sed '/\/my\/cron\/job/s!^!#!'
#0 10 * * 5 /my/cron/job
0 10 * * 5 /other/cron/job

Understood on the code posting. I will keep this in mind for future posts.
This works great. Thanks for the quick response, much appreciated.