[Membership plugin] Payment gateway : choice of currencies

Hi,
I'm currently setting a membership site through the use of WPMU Membership pluging BUT I'm in Europe and want to charge my customers in Euro.
Is there a way to activate the choice of currencies in Paypal ?
I've seen (and used) other membership plugins that offered that option. I've turned to WPMU for the dripping feature of the membership plugin but having to charge in $ is a deal breaker. Would it be hard to implement that feature ?
In the meantime, is there a way I can charge my customers with my own (say) paypal buttons and still use the plugin ?

I'll rephrase it just to be sure I'm clear enough (english isn't my native language so i'm always afraid I'm misunderstood):
I'd like either:
1) to have an option to choose my currency within the plugin
or
2) to use my own paypal code with the plugin

Thank you,
Anael