WSO pro has an IPN option, just pass the url of you script that will receive the paypal ipn while setting up a new product.

Yea but i do not want to pass my ipn inside paypal to wsopro. I use my ipn for many things. That is why i want to know if they make use of custom ipn variable.

I have not used wsopro Before and I do need to know if i can add custom variables myself to the wsopro button such as notify_url or if wsopro do it themself.

Regards,
MoonWolf

Have you contacted warriorplus about this, I think they might know this.

This is a common issue as many people use paypal for more then one product, yet paypal only allows one ipn.
Andrew Hunter, who's also a WF member, has a nice little plugin to handle this issue, and it's pretty cheap.
The Sonic IPN plugin. (Not aff link).

That could also be a solution to forward the ipn myself. however then Another question. Does wsopro accept outside urls to post ipn data? The button solution with a custom variable would still be the easiest option.

WSO Pro will forward the IPN data received from Paypal to another system of your choosing.

See the WSOPro Knowledgebase