Theres a script on codeshare that may help. I've never had to use it myself though and not 100% sure you can import on another device but thought you'd appreciate the link nonetheless. Something to try at least.
Which specific 9.x version are your policies? How many policies do you have? How complex are the policies you've deployed?
There were some significant improvements and changes to ASM in 9.4.2. If your policies are from before that I'd strongly consider rewriting them from scratch on v10. You can take a lot of the basics from the old v9 policy and configure it manually in the v10 policy, but so much changed in 9.4.2 that I don't think it's useful to use the policies which are automatically generated by ASM in an upgrade from pre-9.4.2 to 9.4.2+. You might also consider using the 10.2.2 policy builder to automatically start new policies.
I'd also talk with your local F5 or partner SE to get recommendations based on your specific scenario.
Thanks guys, this project is still in the pre-sales stage, I do not know about the exact version of the version 9 box as of now. I guess reconfiguration of the policies from scratch might be the best option.