I have 1 of 4 large wooden front porch posts that has started to rot at the bottom. I do not want to replace all 4 columns just because the lower 1/3 of one column is bad.

Can someone with carpentry skills do a partial replace on the square lower part of a column? Is there a way to take off the rot and join the old upper portion to a newer bottom portion?

The rot has NOT gotten up into the turned part of the post yet. My other option would be to buy one single replacement column but I don't have any retailers locally that are selling them this large any more. Are there any ****** resources for matching up old column sytles? We have a 1988 Ranch Style house so it seems like someone somewhere would still be offering the older larger posts.