Yeah, just do
str_cpy(globalStr, "Hello?");
And it wont trash your heap.
But if you need to allocate memory on the heap then you HAVE to delete it. If you wont and call it like every frame it will eat your memory in 2 mins xD
Best is to read up on heap and stack and maybe some asm.
Short explenation:
Heap will keep data
Stack will keep data till it calls a return
If you want some bigger explanation I could write a bit, but I guess Sid could also write one of his nice to read posts =D (Enjoy them every time xD)