This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 幐 is uncertain. It visually contains 巾 (cloth) on the left and a complex right side that may have originally contributed sound or meaning, but the details are unclear.
Since the meaning is unclear, focus on the shape: 巾 (cloth) on the left suggests something related to fabric, but the overall character is rare and its use is uncertain.
For トウ, imagine a toe (トウ) wrapped in a cloth (巾) from this mysterious kanji: toe -> トウ.