You can try to feed the installer using shell redirection, even from a file, or even from the same file.
Code:
$ cat << EOF
this is just an example
just imagine that "cat" is an installer
EOF
this is just an example
just imagine that "echo" is an installer
This can't always be done, of course. It depends on the app itself.
Another alternative is to uncompress the file using 7z or whatever, then do your own.