This is not the fastest way to implement it but it gives you an idea of how it works:
 Code:
Dim $objSysInfo, $arrDN, $strDN
$objSysInfo = CreateObject("ADSystemInfo")
$arrDN = Split($objSysInfo.UserName,",")
For Each $strDN in $arrDN
  If $strDN = "OU=TheNameOfMyOU"
    Use X: \\server\share
  EndIf
Next