I'm worried - Will my page rank go down if...

[Centertainment1]

Recently I made a blog, and most of the time I was focusing on increasing the number of backlinks to the site and SEO. I've just started actually using it, and have a page rank of 4. The blog is located at http://sciutopia.wordpress.com.

Here's the issue. This is 1 month after I created the blog, which is quite incredible, seeing as I somehow got the page rank up so quickly. I have a new forum located at www.scienceutopia.com. But if I were to now set up a subdomain and change the nameservers to those of my wordpress site, therefore meaning that I could only access it through the subdomain domain of my site, and not sciutopia.wordpress.com, would it affect the pagerank? Because one of the factors that tend to affect the page rank of a site is the number of links linking to it, and they would all be linking to sciutopia.wordpress.com, not my domain. So would my page rank go down if I were now to set up the blog so that it is only accessible through my domain at, say, blog.scienceutopia.com?

Thanks

[MajorTom]

Just use 301 redirects and you should have no problem moving any site.

[Centertainment1]

How would I use a 301 redirect on a wordpress hosted site?

Edit - I found out that unfortunately I can't

What would be the easiest way of moving it to my domain without payment?