We have an EVI-D70 camera that we use for our webcasts.
I purchased a VISCA control cable for around $15 on Ebay that comes with a 20' cable and a serial adapter. The length of cable can be extended by adding a RJ-45 coupler and using a long Cat5 cable.
I have downloaded some free EVI-D30 control software on the internet and have successfully used it to remotely control the camera. The software gives greater control and precision than using the IR remote. The software is not advanced, but you do get what you pay for with it -- basic functionality (zoom control, pan control, memory position set and recall, etc.)
I run the S-video out of the camera to the webcast communicator and then I run the RCA video out into a USB Dazzle video capture device connected to the USB port on the same laptop that the VISCA/Serial cable is connected to for controlling the camera. That way I can see the real-time image on the laptop and run the camera control software at the same time. I simply tape the cables down along the floor to where I'm sitting with the controlling laptop -- which is either at the back of the chapel (in front of the cultural hall) or up on the stand at the clerk's table.
It has worked very well -- the only challenge is making sure I have a laptop that has a serial port. It would probably work to use a USB to Serial adapter, but I have not tried that yet.
Cable -- search Ebay for "Sony EVI-D30 VISCA control cable"
Software -- search google for "evi-d30 software" or visit the following link:
http://www.elims.org/evi-d30.htm and download the "Camera control program from Sony" -- I have no affiliation with this website. This is the software that I have been using.