You may have done all the following, but it may help to check your steps.
METHOD A
Use the SME server to add a network printer -got to the SME control panel "Printers" and add the printer.
You need to give it a name that the network can use and find (eg oki350 as you have in your example). You need to know the network address of the printer (eg 192.168.x.y) and finally, set it to "Raw".
If you do all of this, it is now a "browseable" printer - WinXP can see it on the network when you add the printer to your WinXP box.
Use the Add Printer Wizard in XP
This is the best way to add networkprinters, because it reaches a point where it asks you if you want the printer drivers installed.
If it is a stock standard printer driver that WInXP knows, just choose it. If it is something else, install the printer drivers first, then use the Wizard - it will find the drivers on your WinXP box. And the main thing is that the connection is permanent - or it should be.
With those two steps, the printer should be permanently installed for your WinXP box.
If not, then I think you may have a WinXP problem.
METHOD B
There is another way, where you use WinXP to install the printer directly pointing to the IP address of the printer.
On the XP box, open the Add Printer Wizard.
Choose "Local printer.....".
Untick "Automatically detect...." (not sure if you need to do this last step, but I always do). Click "Next"
Tick "Create a new port" and choose "Standard TCP/IP Port from the drop-down list". Click "Next"
At this point it starts the "Add Standard TCP/IP Port Wizrd". Click "Next"
Put in the IP of the printer (eg 192.168.x.y) - it fills in the Port Name for you. (eg IP_192.168.x.y) and tries to connect.
You then complete with details of what type of printer it is as normal...you may have to use the driver CD at this point, or install the drivers for the printer first (as in my first example above).
You may know all this and have already tried but I hope it is of some use.
By the way, with "net use" commands, you can add modifiers at the end
eg net use lpt1: \\myserver\ok350 /persistent:yes should permanently add the connection
net use lpt1: \\myserver\ok350 /persistent:no adds it just for this session.
These commands can be included in a logon script (or autoexec.bat prerhaps)
I use a similar version to map a network drive at logon:
net use x: \\myserver\mydata /persistent:no
Good luck
Cheers
Ian