I have modified my previous reply.
Please refer the below link.
http://www.aspforums.net/Threads/202049/Convert-any-ms-office-doc-to-pdf/Replies/1#Replies
If you want to execute cmd from code behind then refer the below code.
Refer the below code.
C#
string cmdText = "/c /pt";
System.Diagnostics.Process.Start("CMD.exe", cmdText);
VB.Net
Dim cmdText As String = "/c /pt"
System.Diagnostics.Process.Start("CMD.exe", cmdText)