Validating a string with specific custom date format in VbScript

I have search for a vbscript function to meet my requirement of validating a date string with a specific date format but my badluck i am unable to find which meets my requirement.So i finally decide to write my own script to fulfill my requirement.
My custom function to validate / check for a custom date format in a date string it returns True or False
Assumptions:
Date format contains date in DD format, month in MM or MMM format, year in YY or YYYY format.
e.g. DD-MM-YYYY or MM-DD-YYYY or YY-DD-MM or MM-YY-DD or MM/YY/DD etc
If year is in YY then it consider it to be 2000 year only e.g. 10-15-02 and format is YY-DD-MM
then it will check for a valid date of 2010 15th Feb .

Function CheckDate(strDate,strFormat)
strFormat=UCase(strFormat)
If(Len(strDate)=Len(strFormat)) Then 
 Dim iStartD,iLastD,iStartM,iLastM,iStartY,iLastY,iFirstSeperator,iLastSeperator
 
 iStartD=InStr(1,strFormat,"D")
 iLastD=InStrRev(strFormat,"D")
 iStartM=InStr(1,strFormat,"M")
 iLastM=InStrRev(strFormat,"M")
 iStartY=InStr(1,strFormat,"Y")
 iLastY=InStrRev(strFormat,"Y")
 For i=1 To Len(strFormat)
  Dim x,seperators
  seperators="/.-|:"
  x=Mid(strFormat,i,1)
  If(InStr(seperators,x)>0) Then
   iFirstSeperator=InStr(strFormat,x)
   iLastSeperator=InStrRev(strFormat,x)
   Exit For 
  End if
 Next
 'WScript.Echo iFirstSeperator&" "&iLastSeperator
 
 'WScript.Echo iStartD&" "&iLastD&" "&iStartM&" "&iLastM&" "&iStartY&" "&iLastY
 
 Dim vDate,vMonth,vYear,validDate
 validDate=False
 
 If(iLastD>1) Then 
  vDate=Mid(strDate,iStartD,iLastD-iStartD+1)
  Else
  vDate="01"
 End If 
 If(iLastM>1) Then 
  vMonth=Mid(strDate,iStartM,iLastM-iStartM+1)
  Else
  vMonth="01"
 End If 
 If(iLastY>1) Then 
  vYear=Mid(strDate,iStartY,iLastY-iStartY+1)
  Else
  vYear="2010"
 End If 
 If(Not Len(vYear)>2)Then 
 vYear="20"&vYear
 End If 
 'WScript.Echo vDate &" "&vMonth&" "&vYear
 If(Len(vMonth)>2) Then
  WScript.Echo IsDate(vDate&"-"&vMonth&"-"&vYear)
  If(IsDate(vDate&"-"&vMonth&"-"&vYear)) Then 
   WScript.Echo CDate(vDate&"-"&vMonth&"-"&vYear)
   validDate=True
  End If 
 ElseIf(Len(vMonth)<3) Then
  WScript.Echo IsDate(vYear&"/"&vMonth&"/"&vDate)
  If(IsDate(vYear&"/"&vMonth&"/"&vDate))Then 
  WScript.Echo CDate(vYear&"/"&vMonth&"/"&vDate)
   validDate=True
  End if
 End If 
 
 If(iFirstSeperator>1 And validDate=True) Then 
  If(Mid(strFormat,iFirstSeperator,1)=Mid(strDate,iFirstSeperator,1) And Mid(strFormat,iLastSeperator,1)=Mid(strDate,iLastSeperator,1)) Then 
  validDate=True
  Else
  validDate=False
  End If
 End If 
 
 Else
 validDate=False
 End If


CheckDate=validDate
End Function