create connect string for informix using intersolv driver

I need help in creating the connect string to connect to the informix database using the Intersolv SequeLink driver. I could create the ODBC manually and use the DSN in my script to connect to the database. But, we have several sites and I cant create that many ODBC. So, I am trying connect to each database thru script (vbscript or excel vba). Here is the information that I provide, when I create the ODBC manually. (Is there any way to give the screenshot in this forum?)

Driver = INTERSOLV 3.10 32-BIT SequeLink
Data Source Name = st2501
SequeLink Data Source Name = st2501
Service
Type = INFORMIX7
Name = SLInformix
Database = site
User Name = prog
Password = *********
Host (server/router)
Type = UNIX
User Name = prog
Password = *********
Network
Type = TCP/IP
Host=site2501

I have searched internet and found several connect string and none of them worked. The error message said "sufficient information has not been provided". I can tell you that I didnt give all the above information in the connect string. I dont know the syntax for that.

I tried creating one DSN manually and tried to use that for other sites by overriding just the host information. But that also didnt work.

Please help me in writing te connect string for the above ODBC DSN. Thanks.

Raj.