If the witness appears before such officer and makes oath or affirmation that the testator signed the writing annexed to the commission, as his last will, or that the testator signed the writing, of which the photostatic copy annexed to such commission is a copy as his last will, or that some other person signed it by his direction, and in his presence, that the witness subscribed his name thereto in the presence of testator, the testimony so taken shall have the same force as if taken before the court or clerk.
§ 473.060, RSMo