1998 chevy lumina, shifter on steering column,won't shift

Is this console shift or column shift? If column shift, I'd have to look under the hood or under the vehicle at the shift linkages to see if the linkages are moving? Is this fwd or rwd, I haven't looked up any info on your vehicle?
If column shift and the shift linkages don't move, the shifter in the column may be broken, if that is the case, I swap out the steering column for one with a good shifter.
I don't know your model year? If the ignition switch is on the steering column, I don't know if it might effect your security system, where applicable? You might be swapping one problem for another, hope not? Something to think about.

if the shift process is through a cable then check the cable for wear and fraying, rust or dry. If it is through linkage check for worn /rusted /tight connections

there is no linkage there is a cable fron the transmission to steering column nylon gromets on each end break replace shifter cable

Before you go too far, your problem might be as simple as mine was. The gear shift knob had slipped and was not down far enough on the shaft to engage the release mechanism.

check linkage for binding,or out of adjustment, and check for bad motor support

that would be your shift lever assembly and yes it can bwe fixed and its fairly easy

get a new lever punch out the roll pin that holds it in.replace lever and reinstall roll pin

SHIFTER LOCKED IN PLACE

1. Remove the instrument panel cover below the steering column, then remove the steering column shrouds to gain access to the brake transmission shift interlock (BTSI) solenoid. The solenoid is part of the interlock cable assembly.
2. Disconnect the wire connector from the rear of the BTSI solenoid.
3. Insert the ignition key and turn it to the ON position.
4. With the brakes applied, try moving the shifter out of the PARK position.

• If the lever now moves freely in and out of PARK, perform the Circuit Test below.
• If the shift lever still does not move from the PARK position, remove the BTSI solenoid from the shift lever assembly. If the shift lever now moves freely in and out of the park position, the BTSI solenoid is faulty and the interlock cable must be replaced. If the shift lever still does not move from the park position, the problem is in the shift lever assembly or the ignition interlock cassette

Have someone look @ linkage on trans. while someone moves shift lever thru the gears. If lever @ trans doesn't move then its in the linkage between the column and trans. (possible clip or pin broken @ linkage jounts). If lever @ trans moves then its a trans. internal prob.

At the rear of the shifter lever on the column you find 2 screws. These screws had worked themselves loose causing the shifter to become loose and sloppy.