I would suggest you look at one of these methods.
As you are using a scripting language Asp / Asp.Net you can:
1) Use a database and File System Object
Dynamic Includes can't be used as these are processed before the QueryString! Bother!
Within the database there is variable for the dynamic file reference and with FSO you suck this onto your page. Each record would have it own unique file reference or simply use the Querystring
page=nba/teams/teams.aspx
Code:
IncFileName = Request.QueryString("page")
incFile = Server.MapPath(IncFileName)
fs = Server.CreateObject("Scripting.FileSystemObject")
tmpFile = fs.OpenTextFile(incFile, 1, False)
tmpStr=tmpFile.readall
response.write(tmpStr)
tmpfile.close
tmpfile=nothing
fs=nothing
Simon