在线等! ScriptControl 执行自定义公式遇到的问题

我想实现如下 的表达式
Grid 表格控件

strF= "Form1.Grid.TextMatrix(Form1.Grid.row,8)=val(Form1.Grid.TextMatrix(Form1.Grid.row,5))*0.9 "


Dim SC As New ScriptControl
SC.Language = "VBscript "
SC.AddObject "Form1 ", Form1
SC.ExecuteStatement strF
SC.Eval strF
Set SC = Nothing


++++++++++++++++++++++++++++++++++
出错 :类型不匹配 'val '
谢谢!

[解决办法]
debug .print Form1.Grid.TextMatrix(Form1.Grid.row,5)