vba userform - how to sum values decimal and integer?

Hello ppla

i have this workbook that i colect information about several stuff and one of them is windows weight and height.

then if an window is "horizontal" it sums the values and substracts in the roof area.

my problem is that it all works well when the values are integer like 1, 4 , 15
but if there are decimal it doesnt work. how can i surpass this ?

for i = 1 to 21
name_tp = "vao" & i & "_TP"
If Me.Controls(name_tp).Value = "Cob. Interior" Then
              If Range("'Inicio'!AE$603").Value = 0 Then
              Range("'Inicio'!AE$603").Value = "=+(" & Me.Controls(name_l).Value & ")*(" & Me.Controls(name_h).Value & ")"
               Else
               Range("'Inicio'!AE$603").Value = "=" & Range("'Inicio'!AE$603").Value & "+" & "(" & Me.Controls(name_l).Value & ")*(" & Me.Controls(name_h).Value & ")"
               End If
            End If
next i

thx in advanced

p.s. if someone isnt quite understanding what i am trying to achieve please ask, because my english is not 100%