Try this. This assumes that you have one network adapter, or at least that the first adapter enumerated is the one that you are interested in.

Code:
$sMyNetwork=IPDecimal(IPDecimal(EnumIpInfo(0,0)) & IPDecimal(EnumIpInfo(0,1)))
Select
Case $sMyNetwork='172.16.136.0' OR $sMyNetwork='172.16.137.0'
	"Will Map X Drive" ?
	Use X: /delete /persistent
	use X: "\\apps\CDRoms"
	If @ERROR "ERROR: Could not map X: ["+@ERROR+"] "+@SERROR+@CRLF EndIf
Case "Default"
	"Will not map X drive" ?
EndSelect
 
; IPDecimal Dotted Quad <-> Network number conversion
Function IPDecimal($v)
	If InStr($v,".")
		For Each $v In Split($v,".") $IPDecimal=$IPDecimal+Right("00"+DecToHex($v),2) Next
		$IPDecimal=Val("&"+$IPDecimal)
	Else
		; Convert to hex and zero fill to 32 bit.
		; This avoids problems caused by twos complement representation
		$v=Right("00000000"+DecToHex($v),8)
		While $v
			$IPDecimal=$IPDecimal+"."+Execute("Exit &"+Left($v,2))
			$v=SubStr($v,3)
		Loop
		$IPDecimal=SubStr($IPDecimal,2)
	EndIf
	Exit 0
EndFunction