Of coarse, restart files can still be used with the "read_restart"
command. After loading the restart file, you can use the "write_data"
command to create a data file.
P.S. If the parameters of your force-field aren't changing, I
suggest put those in pair_coeff, bond_coeff, angle_coeff,
dihedral_coeff, and improper_coeff commands in a script and "include"
them later after you load the restart file. That's always a
fool-proof way to guarantee those parameters remain unchained. Not
everyone agrees with me that this is a good idea but if you are using
some weird user-contributed force-field style (such as mine), all bets
are off. Cheers