[TYPO3-english] How to build select field in Powermail using TS?

[Benoit Montereau]

My webform built on Powermail should contain a select field with options
depending on a parameter transmitted in the URL.
Basically the default would be to have 3 options (ie. 1, 2, 3).
Now if a specific url parameter is provided (ie. max=1), then the select
should only display the option 1.
I don't think it's possible only using the Powermail flexform, so I'm
wondering if it's possible to get the working by creating the field with
Typoscript.
I hope someone can help me with this issue.
Regards,
BM