Single view on multiple pages 1) I created a content type Portfolio-Item. In this type a text field Project-Url was defined.

2) I created a view containing a gallery using jQFX module displaying content of Portofolio-Item elements which where published.

I wan't to add this view to different pages containing different projects portfolios. 

a) Is it possible to add a "filter criteria" or "contextual filter" that would compere the Project-Url field with page URL and filter available Portfolio-Item's to display only proper one's. ?

b) Is there any easy way to achieve this?

c) Can contextual filter's be used with regular expressions?
I would recommend you to use a Viewfield or the EVA Module. With both of them you can attach a view to an entity and add arguments. I personally prefer EVA to do stuff like this. Very handy and allows you to use the same in different contexts without exposing it to the site admin directly.