Can i convert STL  files to a SOLID PART

I realize its not possible to have the deign intent (tree) but i would like to import the STL file as a solid so i can add features to the part.

It would be best if i can import directly and maybe solidify the STL file to one component instead of multi triangular faces.

I would not mind using an intermediate step like importing the file as STL and then exporting as STP and then reimporting it as a Solid block file

If thats not possible is there a value converter out there that can convert STL to solid objects ?

TIA