As HighCore said, there's no C# equivalent to VB's With
block. Here's the equivalent C# code:
myRow = ProductRangeA.Rows.Count;
myValue = ProductRangeA.Value;
myRow = ProductRangeB.Columns.Count;
myValue = ProductRangeB.Value;
Since you can't avoid typing ProductRangeA and ProductRangeB twice each, you can reduce typing by using shorter variable names. That can make the code more difficult to understand, of course.