It sounded like you just wanted to move the character to a different spot on the same map (designers usually put the building interiors on the same map as the "outside" town). If you want to change the map
and start the character on a specific spot in that map, it's significantly trickier. You can't put the character where you want him to go in the same block of code, because calling map() halts the flow of code. So what do you do? Well, this is the tricky part...
Every V3 map has a function that's executed when it loads. If you're using maped3 (and I guess you must be), you can find this under Map --> Properties. Set "startup script" to some function you want to call when the map loads (without the parentheses following the function name). It has to be a function with no parameters, but it can be from either system.vc or the map vc file. Now, if you always know where the player is going to appear when the map loads you can just stick him there in the startup function. I'd recommend something a little more advanced, however.
Are you putting the player chr on your map in maped, or generating it using EntitySpawn? I guess you're doing the former, but whatever, this works either way:
What you do is something along these lines. Have two global ints, named something like and "newmap_x", "newmap_y". Before you do the mapswitch you set these to where you want the player to go on the new map. Then in the map's startup script you call some map-initialization function, which contains a block of code like this:
// spawn hero entity and set him as player
SetPlayer(EntitySpawn(newmap_x, newmap_y, "darin.chr"));
...or if you already have a player entity set down, you'd set him as player move him to the right place using something like Overkill's code.
Setting the x/y vars each time you do a mapswitch could get a bit annoying, so (assuming you used this method) you might also define a custom mapswitch function along the lines of:
SexyMapSwitch(string mapname, int xc, int yc) {
newmap_x = xc;
newmap_y = yc;
// Some kind of sexy fadeout could go here!
Map(mapname);
}