If UTF-8 is unicode, and you want just the bytes of the ASCII characters, you can do this (built in conversion in VBA):

UTF-F is is a variable-character-length encoding of Unicode that pays careful attention to not confusing code that looks for chars 1-127 (classic ASCII), thus encoding Unicode chars in standard 8-bit strings, but all bytes with values 1-127 are what they appear to be.

Learn more here:
 http://en.wikipedia.org/wiki/Utf-8

So, the example you posted doesn't do what i need. I need to take a string that I have pulled into a string from a textstream.ReadLine() command and I need to convert it using UTF-8 decoder into a Unicode string decoded from the encoded string. For instance, a 10 byte (10 8-bit bytes) might convert into a 2-10 character Unicode string after variable-length UTF-8 decoding.

this decoding is built into VB, but seems to be offlimits to VBA clients and ASP? Is there no way to do this? BAsically, I need to use the System.Text.UTF8Encoding class from VBA and it seems like it isn't available from the VBA world.

Any ideas?