vb.net database query [generation of SQL Strings]

Data | database | String---------SQL generation----------
A task is a multiple-condition query that uses in (X,y) when a user separates a query by commas, but an error occurs when the field corresponding to the database (ACCESS) is a character type, of course! If it is in (' X ', ' y ') there is no problem!
The following code is the operation of the string, which returns ' X ', ' Y '.

'-----Accept the string to be processed-------
Function tool_distest (ByVal textbefore as String)
Dim Textafter () as String
Dim Intnum, Inttextlen, K, I as Integer
Intnum = 1
Inttextlen = Len (Textbefore)
'--------How many query conditions are calculated--------
For i = 1 to Inttextlen
If Mid (Textbefore, I, 1) = "," Then
Intnum = intnum + 1
End If
Next
'-----------------------------------
ReDim Textafter (Intnum)
K = 1
'--------put each condition in the array---------
For i = 1 to Inttextlen
If Mid (Textbefore, I, 1) = "," Then
K + 1
Else
Textafter (k) = Textafter (k) & Mid (Textbefore, I, 1)
End If
Next
'----------------------
Dim strtemp as String
'--------add '----------for each condition
For i = 1 to Intnum
strtemp = Textafter (i)
Textafter (i) = "'" & strtemp & "'"
Next
'----------------------
strtemp = ""
'------Add a separator condition, '------
For i = 1 to Intnum
strtemp = strtemp & Textafter (i) & ","
Next
'------------------
'------Remove the last,------
strtemp = Mid (strtemp, 1, Len (strtemp)-1)
'-------------------
Return strtemp
End Function

Finally in SQL Server to try again, found that SQL Server query in (x,y) to query the character type is OK, (SQL Server is more than access strengths, hehe)
---------End-------