I don't know your particular GPS but if in your handbook it says that there is an output of NMEA 0183 version 2.0 or above then the answer is Yes.
The simplest way to try this at home is to get hold of a copy of Autoroute 2000 and sus out the right conections to your comm ports (not straightforward) and away you go.
Yes David you can, Garmin sell a serial port lead that will connect your Garmin 12 to your Laptop. I use it with SeaPro 2000 for planning routes, the only draw back is that you can not use your 12 volt lead at the same time.
I use a Garmin 12 XL interfaced through com1 onto laptop using Tsunamis 99's exellent navigational
software, the lead into the garmin also splits and plugs into the 12v fag lighter point thus I don't
need to rely on batteries for the Garmin. The Laptop runs off inverter so same again no battery
probs. This set up I have used all season with great results.
Or you could make your own and save the silly amount of money Garmin want. Garmin power cable £10. Add a 20p serial plug to it and it becomes a £30 PC data cable. I don't mind paying the tenner for the power cable as it has the Garmin plug and saves a lot of messing. Then just find a knackered mouse and pull the wire and plug off it and you have just saved having to buy a serial plug as well.
The link below has nice little pictures of the pin numbers and which wire goes where.
I use ozi exxplorer www.oziexplorer.com to my garmin, Garmin Data leads cost a fortune, but a way round is to visit maplin or similar & get the sockets to go over the garmin pins, then use some silicone sealant to cast round the pins.
My tip is to use a bit of cling film to line the socket first.