OK, that was weird, I am replying in order to add text to the message....
In the meantime, I answered the question I was going to ask. I was going to ask how to run a block of Oscript. The answer is not in the Run or Debug menus but if you right click on the script object and selecting Run Script or Debug Script from the contextual menu.
-Hugh
Are you trying to run a particular function/script, or just arbitrary OScript code? It sounds like you've found out how to do the former. For the latter, I create a script file in the root of my project folder (i.e. living along side the srcmodules folder) that I just use as a scratch pad. I write whatever code I want to run in it, then right it either by right-click | Run Script, or just using the Ctrl+. hotkey.