first you need to model your gun with a appear animation and a reload animation 3ds max or milkshape is good for this
then save one copy as hud.x with relevent skins and sounds and pop it in a folder in
C:\Program Files\The Game Creators\FPS Creator\Files\gamecore\Guns\scifi\lazerpistol
then save another copy as vweap.x pop in the same directory
and then create a fpe file
;Header
desc = lazerpistol
;AI
aiinit = appear2.fpi
aimain = weapon.fpi
aidestroy = disappear2.fpi
;Spawn
spawnmax = 1
spawndelay = 3000
spawnqty = 1
;Orientation
model = lazerpistol.X
scale = 100
rotx = 1
texturepath = gamecore\Guns\scifi\lazerpistol
textured = gamecore\Guns\scifi\lazerpistol\gun_D2.tga
reducetexture = -1
transparency = 1
isimmobile = 1
;Identity Details
isweapon = scifi\lazerpistol
quantity = 1
speed = 100
;Decals
decalmax = 1
decal0 = glowzone
and pop that in
C:\Program Files\The Game Creators\FPS Creator\Files\entitybank\lazerpistol
and you should end up with some thing like
http://forum.thegamecreators.com/xt/xt_apollo_pic.php?i=643172
hope that helps
here is a animated template file to work from