This should give you an idea:
url(r'^file/vnc/$', 'myapp.views.vnc', name='vnc-view'),
views.py
from django.views.decorators.http import require_POST
@require_POST
def vnc(request):
ip = request.POST.get('ip', None)
response = HttpResponse(ip, content_type='application/octet-stream')
# If you don't want the file to be downloaded immediately, then remove next line
response['Content-Disposition'] = 'attachment; filename="ip.vnc"'
return response
template
<form method="POST" action="{% url 'vnc-view' %}">{% csrf_token %}
<input type="hidden" name="ip" value="127.0.0.1" />
<input type="submit" name="submit" value="Create VNC to 127.0.0.1" />
</form>