can AnchoredPDBcreator be used for inserting a helical anchor onto a surface helix?
I think you're asking, "can AnchoredPDBCreator be used to add helical residues to the middle of an existing helix"?
If that's what you're asking, the answer is technically yes but functionally probably not. I mean, the code will run, but it will likely ruin your intended secondary structure - it assumes it's working with a loop. It would work best to replace the entire helix so that AnchoredPDBCreator can play only with the flexible endpoints.
ok so can i go ahead with replacing a surface helix with my helix?
You should certainly try. If you replace a whole helix it will probably work well enough.