Archer30, you don't need to get semi-formed string. You can modify existing string object by appending another string (line) to it with your custom text.
!?FU(arch_OnAfterSetArtLuckDesc);
!#VA(hook:x);
!!UN:Cx1/(STRUCT_HOOK_CONTEXT_EBP)/4/?(ebp:y);
!!UN:C(ebp)/-32/4/?(ptr:y);
...
!!SN:E.../.../^you appended string, probably with newline^/length of your appended string;