Hello Nick
the string is:
HYPERLINK("http://192.168.1.88:5481/make_call.php?extnum=127&vmpin=127&to="&Phone,"Click here to call this contact with 3CX") wich generates
http://192.168.1.88:5481/make_call.php?extnum=127&vmpin=127&to=050259975
even running like localhost i get the same 404 The requested URL /make_call.php was not found on this server.
the server box is at 192.168.1.88
the ext # 127
regards