post_tags

Hi

I am not sure if I am writing in the right section. please let me know if I should post this somewhere else.

So here is my situation:

I am using a custom form on wordpress with it’s own template. I have a field that says tags but I want to link this into the post_tags loop. I can set it up without this easily but I really wanted it tied into the post-tags taxonomy so it works the same. I tried looking at the code but since it’s all all separated I’m having a little trouble determining how to recreate or connect into this.
Does anyone have any suggestions or advice?
thanks