The following VBA example creates a blend, attaches it to a path, and specifies that the blend steps should be placed at a fixed distance of 0.5" from each other.
Sub Test()
Dim sPath As Shape, s1 As Shape, s2 As Shape
Set sPath = ActiveLayer.CreateCurveSegment(0.6, 4.5, 7.8, 8.5, 5.2, 62, 5.3, -96)
Set s1 = ActiveLayer.CreateEllipse2(0.6, 4.5, 1)
Set s2 = s1.Duplicate(7.4, 4)
s1.Fill.UniformColor.RGBAssign 255, 0, 0
s2.Fill.UniformColor.RGBAssign 255, 255, 0
With s1.CreateBlend(s2).Blend
.Path = sPath
.Mode = cdrBlendSpacing
.Spacing = 0.5
End With
End Sub