How do you read an online text document into a variable in powershell?

I don't really know how to code powershell, but it appears to be the best language that's already installed to do what I want. (If there's a better way please tell me haha) What I want to do is to run a flash projector to run an online swf file. That swf file has a different name depending on what version it has, and it updates fairly often. Swf url:

website.com/file#####.swf

version url:

http://ift.tt/204NHQS

Inside the txt is the numbers that get added to the name of the swf. How would I write a powershell that discreetly executes flashplayer to run these things? If I were to write this into a windows shortcut it would look like

flashplayer.exe http://www.website.com/file12345.swf

Problem is that would only work for that particular version.