We have recently reported single-electron tunneling (SET) via a-few-donor QDs at high temperatures in high-concentration selectively-doped SOI-FETs. A central QD works by SET mechanism above 150 Κ at small source-drain bias due to enhanced tunnel barrier. For tuning the tunnel barrier, it becomes critical to understand the impact of the donor-QD location on the SET transport. Here, we report the possibility of probing donor-QDs from center to near the lead edge using high-bias stability diagrams. We also observe and model the changes due to purposely shifted positions of the selectively-doped area.