Conversion Hexadecimal to RGB value VBA Macro

Hello,
I am a student and for a project I need to to adapt the look and feel of my application. To do this, I would first have to analyse some code and enter the colour values in order in an Excel table.
For this I need a column with the hex value of the colour contained in the source code file, the RGB value and a third column that is coloured in the corresponding colour. If the hex or RGB value is changed, the third cell should be changed accordingly. Additionally, a column with the name of the function in which the colour is set.

I enclose here the draft of my work on it.
Today I can convert either from HEX to RGB or RGB to Hex with the help of excel formulas. I tried to convert from rgb to hex with a macro but it doesnīt work.

Can you please help me

Thanks you for the welcome !
And Thank you for the tip but I already know it but I donīt really understand the code. I tried to implement this code :

Public Function ConvertHexToRGB(sHexColor As String, sRGB As String) As Integer
sHexColor = Replace(sHexColor, "#", "")
Select Case UCase(sRGB)
Case "R"
ConvertHexToRGB = CInt("&h" & Left(sHexColor, 2))
Case "G"
ConvertHexToRGB = CInt("&h" & Mid(sHexColor, 3, 2))
Case "B"
ConvertHexToRGB = CInt("&h" & Right(sHexColor, 2))
End Select
End Function

But It doesnīt change anything on my excel sheet

I am so bad at excel I am trying to improuve

Thank you !!

Now a new problem : if I would like to change the hex value without changing the formula how do I do ? Do I have to use this code to switch from HEX value to RGB value ?

Public Function ConvertHexToRGB(sHexColor As String, sRGB As String) As Integer
sHexColor = Replace(sHexColor, "#", "")
Select Case UCase(sRGB)
Case "R"
ConvertHexToRGB = CInt("&h" & Left(sHexColor, 2))
Case "G"
ConvertHexToRGB = CInt("&h" & Mid(sHexColor, 3, 2))
Case "B"
ConvertHexToRGB = CInt("&h" & Right(sHexColor, 2))
End Select
End Function

Because the main goal here is if I want to change the RGB value it will modify the HEX values and the color and If I modify the HEX value it will change the RGB value and so the color I donīt know if you know how to do it ?

This is a very good question This is the only way I know to check and change the modified cells

And do you have an idea on how can we change the HEX value. I was thinking for example with a macro were you can convert Hex to RGB ?

Could it work ?