Hi Theus,
Your .label file should have the following syntax:
#!ascii label , from subject vox2ras=TkReg
154986
0 17.620 -86.460 -14.914 0.0000000000
1 17.044 -86.618 -14.894 0.0000000000
2 15.983 -86.559 -14.974 0.0000000000
Another option is to combine one or several .label files to create a .annot file.
Can you please post the full error message, as well as your .label file?
Francois