First, show us the appraisal. If it's a pole-range weapon it should say so at the top. Occasionally you will find polearms that are not pole-range, because they're meant to be short spears. For example the light spear:

A steel light spear is a heavy thrown and pike melee-ranged weapon.

If it appraises as pole-ranged, then you should be able to use it at pole, but this can be a little finicky. As I understand it, you can attack normally when something closes to pole, but if YOU close to pole and attack you will charge instead (which is still an attack but at greater RT). Therefore you have to type RETREAT once after you reach pole. This will stop you from advancing and you can then attack while at pole. However, most (all?) people have no way of keeping something at pole so your enemy can just keep on advancing to melee.


- Navesi