Supporter: $1 and free trial with Paypal variables

This is something I've been wanting to do for a while...

I would like to have a dollar trial with the supporter subscriptions.

Now setting up recurring payments directly from Paypal work slightly different than it does with the supporter.

WIth the supporter you don't have to do a thing and it works.

Now I've searched through paypal and come across a bunch of variables that makes this possible.

Here are a few of them that seem applicable for doing a trial:

period1
Transaction-specific
(optional) Trial subscription interval in days, weeks, months, years (example: a four-day interval is "period1: 4 D")

period2
Transaction-specific
(optional) Trial subscription interval in days, weeks, months, years

amount1
Transaction-specific
Amount of payment for trial period one for USD payments; otherwise blank (optional)

amount2
Transaction-specific
Amount of payment for trial period two for USD payments; otherwise blank (optional)

mc_amount1
Transaction-specific
Amount of payment for trial period one, regardless of currency (optional)

Question is, how would I use them with the Supporter and where would I start?

For anyone else wanting to do this, there is a complete guide that you can download at https://www.paypalobjects.com/WEBSCR-610-20100112-1/en_US/AU/pdf/PP_WebsitePaymentsStandard_IntegrationGuide.pdf

(not sure if it works when logged out)

Thanks,

George