Enchant item

You touch an item being forged.

Then you cast another spell on the item being forged.

Then you expand a spell slot for the number of charges you want.

If you don't want spells then expand a spell slot. The sword has a modifier equal to the spell slot you used.

If you want special effect talk to the DM.

If you want the item to regain charges then you expand a 5th level spell slot

If you want the magic to not be dispel able then you must expand 5th level spell slot.

This spell cannot make an artifact.

The effect can only be dispelled by divine intervention or a 9th level dispel magic(as long as you didn't expand that 5th level spell slot.