Why would you think you can’t use PHP now? Even if your host doesn’t have it, it’s quite easy to install. Asking your host to do it is normally fine (or worse case scenario, you do it yourself)
If you really don’t have the option to use PHP on your new server, you might be better asking the question in the ASP section of the forum, though as above Windows in general can have PHP support installed on it.
Thanks for your replies - It sounds like I will be able to upgrade my GoDaddy account to Windows IIS 7 which includes PHP so no need to change to ASP for the forms.
Another word of advice - invest in a VPS for $10 a month, and manage your own server. Stay in control of the software you deploy on it, maximize security, and learn devops on the way. It’s far, far less complex than people would have you believe. Here’s my referral link for DigitalOcean if you’re interested, this gives us both some extra credit.