Unknow number of parameters for batch file

[Michaeljc70]

I need to write a batch file that can be passed one to many parameters. I need to call another program with those parameters, plus one other possibly (based on some other logic) and than add on the last parameter (which is a filename really).

For example:
The batch file is called with -i:abc -xqr -l:hjk filename.txt

I need to grab the first 3 params, add 1 more and then add the last:
-i:abc -xqr -l:hjk -p:xxxx filename.txt

Any ideas on how to most easily do this?