gabin,
I use SE and generally just consider it, like any other Program, to be a tool rather than a job in itself.
That said, at my current position the thing that got me in the door was that they needed someone who was strong in Solid Edge and had a background in a field with fairly stringent documentation practices. My other Engineering skills were secondary!
You say Solid Edge Designer, so is this a designer/draftsman position rather than a mainstream Engineering position? Do you have any experience on SE?
What Engineering field is the actual company in? Unless you're some kind of SE expert, and that's what they're looking for, then my guess is they'll be more interested in relevant general skills.
For instance if it's a general designer/draftsman post then they may ask you about relevant drafting standards etc. Perhaps GD&T and/or tolerance analysis etc.
If you haven't used SE before spend some time researching it so at least you have some idea about it (look on this sites SE forum if yo like but the SE/Siemans home page and a google search may be better for the high level overview you need) but I'd worry more about other aspects of the job.
I second most of the previous posts.
KENAT, probably the least qualified checker you'll ever meet...