remedy of coram nobis is a viable means for challenging criminal convictions. It may be used when no other remedy is available, but may not be used to supplant relief through direct appeal, post-judgment motion or PCR petition. ¶ 17. Applying this principle to defendant’s situation, we conclude that defendant was eligible to file a PCR petition and thus precluded from seeking relief through coram nobis. A person “who is in custody under sentence” may bring a PCR petition “to vacate, set aside or correct the sentence.” 13 V.S.A. § 7131. A person is “in custody” for purposes of the PCR statute if he is serving a sentence enhanced by the challenged conviction. In re Stewart, 140 Vt. 351, 359-60, 438 A.2d 1106, 1109 (1981); see State v. Boskind, 174 Vt. 184, 192, 807 A.2d 358, 365 (2002) (<HOLDING>). ¶ 18. Thus, although defendant is no longer
holding that due to statute defendant cannot collaterally attack prior convictions used to enhance sentence unless in violation of the right to counsel holding that prior felony drug convictions that fall within the conspiracy period may be used to enhance the defendants sentence if the conspiracy continued after his earlier convictions were final holding that where defendants seek to challenge predicate convictions used to enhance current sentence proper avenue for relief is through pcr proceeding holding that  5g13c applied where defendants undischarged sentence resulted from multiple convictions only one of which was used to enhance his instant sentence holding amended language gives district courts discretion to permit collateral attack on prior convictions used to enhance sentence