I read that you can edit the starting tiberium in the skirmish.ini file which is in the game's application data folder (in documents and settings). I just have the demo installed, but I changed the 10000 to another number and it works. I am just wondering what all these other settings do. I know I can just change them and see what happens, but I was hoping to find a description online. I'll post the contents of the file. Keep in mind that this comes from the demo, not the full game.
Rts:GameInfo = M=281data/maps/official/map_mp_2_black5;MC=8DE1302;MS=0;SD=369563401;GSID=3BD3;GT=-1;PC=-1;RU=1 100 10000 0 0 10 0 1 -1 -1 -1 -1 -1 ;S=HAustin,0,0,TT,0,6,0,-1,0,1,-1:CE,6,7,-1,-1,0,0:X:X:X:X:X:X:;
Rts:Map = Data_5Cmaps_5Cofficial_5CMAP_5FMP_5F2_5FBLACK5_5CMAP_5FMP_5F2_5FBLACK5_2Emap
Rts:GameInfo = M=281data/maps/official/map_mp_2_black5;MC=8DE1302;MS=0;SD=369563401;GSID=3BD3;GT=-1;PC=-1;RU=1 100 10000 0 0 10 0 1 -1 -1 -1 -1 -1 ;S=HAustin,0,0,TT,0,6,0,-1,0,1,-1:CE,6,7,-1,-1,0,0:X:X:X:X:X:X:;
Rts:Map = Data_5Cmaps_5Cofficial_5CMAP_5FMP_5F2_5FBLACK5_5CMAP_5FMP_5F2_5FBLACK5_2Emap