Having just looked at one of my old VB programs that offers scripting using the Microsoft Scripting thingy, it is as simple as setting object.Language = "VBScript" or similar, being that this is so couldn't you just have the first line of every script file as the script language? (Possibly sensible defaults for .vbs and .js files)
That way people could write their own add-on's in Perl, which has specific text processing advantages, and would be ideal for writing Bot's to do clever auto-responding. If you only distribute JS/VB scripts then people will be sure that all the bundled scripts work, and you can leave it to those that want to give out Perl scripts to supply links to Perl scripting engine etc.
Forum note: Where have forum email notifications gone!!