Abaqus - Import input file with parts instead of assembly

Hi all

May you can provide me any advice how to define an input file which can be read as part and not as assembly in Abaqus ?
I am reviewing an old script of mine and want to use it for a parametric (changing geometries and later also properties) study of this rolled-up structure. The scrip is wirtten in Matlab and generates the nodes which are saved in the input file. All this parts become the assembly.

Matlab code for saving the structure:

file=fopen('nodes.inp','w');

fprintf(file,'%12.f, %12.8f, %12.8f, %12.8f\n',nodes');

fclose(file);

file=fopen('elements.inp','w');

fprintf(file,'%12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f\n',elements');

fclose(file);

file=fopen('sets.inp','w');

for i=1:1:length(sets)

fprintf(file,['*Elset, elset=set',num2str(i),'\n'],elements');

fprintf(file,'%12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f, %12.f\n',sets{1,i}');

fprintf(file,'\n');

end

fclose(file);

Code in main:
*Node
*Include, input=nodes.inp
*Element, type=C3D8
*Include, input=elements.inp
*Include, input=sets.inp