I could do an exchange, its just a bunch of trading scripts adding and subtracting from balances and such.
could that work if i wanted to trade my coin to btc will it be value just in that exchange because i know some coins have different value. I have a altcoin developing which is why i asked.
I have no idea how the prices are determined, but you would have to get the value of BTC from a external API (or do it yourself) and your coin from an external api, but I think markets work by users setting buy and sell orders.