可以的，我用vbs做了一个：
Sub OnClick(Byval Item)
'定义变量
Dim spro,sdsn,sser,scon,conn,ssql,ors,ocom
Dim tagdnsname
Dim m,i
Dim local_begin_time,local_end_time,utc_begin_time,utc_end_time
Dim count_data'数据记录的个数
Dim sum_data'数据记录的累积
Dim aver'平均值
item.Enabled=False
On Error Resume Next
'查询条件,utc开始时间，utc结束时间，时间间隔，catalog
Set tagdnsname=HMIRuntime.Tags("@DatasourceNameRT")
tagdnsname.Read
Set local_begin_time=HMIRuntime.Tags("timebegin")
local_begin_time.read
Set local_end_time=HMIRuntime.Tags("timeend")
local_end_time.Read
utc_begin_time=DateAdd("h",-8,local_begin_time.value)
utc_end_time=DateAdd("h",-8,local_end_time.value)
utc_begin_time=Year(utc_begin_time) & "-" & Month(utc_begin_time) & "-" & Day(utc_begin_time) & " " & Hour(utc_begin_time) & ":" & Minute(utc_begin_time) & ":" & Second(utc_begin_time)
utc_end_time=Year(utc_end_time) & "-" & Month(utc_end_time) & "-" & Day(utc_end_time) & " " & Hour(utc_end_time) & ":" & Minute(utc_end_time) & ":" & Second(utc_end_time)

'创建到数据库的链接
spro = "Provider=WinCCOLEDBProvider.1;"
sdsn = "Catalog=CC_upzjg_11_12_15_14_45_14R;"
sser = "Data Source=.\WinCC"
scon = spro + sdsn + sser
ssql = "Tag:R,('test\testdata'),'2011-12-15 7:27:00','2011-12-15 8:27:00'"
MsgBox "open with:" &vbCr & scon &vbCr &ssql &vbCr
Set conn = CreateObject("ADODB.Connection")
conn.ConnectionString = scon
conn.CursorLocation = 3
conn.Open
Set ors = CreateObject("ADODB.Recordset")
Set ocom = CreateObject("ADODB.Command")
ocom.CommandType = 1
Set ocom.ActiveConnection = conn
ocom.CommandText = ssql
Set ors=ocm.Execute
'读取数据
m=ors.RecordCount
count_data=0.0
sum_data=0.0
If(m>0)Then
Do While Not ors.eof'查看是否到记录结束
sum=sum+ors.fields(0).value
count_data=count_data+1.0
ors.movenext
Loop
Else MsgBox "没有查询到数据............."
item.Enabled=True
Set ors=Nothing
conn.close
Set conn=Nothing
End If
Set ors=Nothing
conn.close
Set conn=Nothing
'写数据到wincc运行系统
aver=sum_data/count_data
HMIRuntime.Tags("average").Write aver
HMIRuntime.Tags("sumdata").Write sum_data
HMIRuntime.Tags("countdata").Write count_data
End Sub
读取一定时间段内的数据计算平均值然后赋值给变量。