Okay i figured it out, all you have to do is add range: bytes downloaded- like this:
WriteLine www, "GET " + webFile$ + " HTTP/1.1"
Writeline www, "Range: bytes=500-"
WriteLine www, "Host: " + webHost$
WriteLine www, "User-Agent: BlitzGet"
WriteLine www, "Accept: */*"
WriteLine www, ""
WriteLine www, "GET " + webFile$ + " HTTP/1.1"
Writeline www, "Range: bytes=500-"
WriteLine www, "Host: " + webHost$
WriteLine www, "User-Agent: BlitzGet"
WriteLine www, "Accept: */*"
WriteLine www, ""