Welcome to AF.
Probly not fixable without a new unit or at least removing the assembly. Which I wouldnt recomend unless you have a GM manual as it's a PITA to take out. Theirs a cable that pulls the window so yours probly is outta wack.
It will also leak in rain....
My 99GT is a leaker too

I thought I had mine sealed up good with silicone sealer,
but last night I got a lap full of rain water
Might be able to find a used sun roof in a salvage yard,
good luck on getting it apart