Skip a String from Replace, if it has any suffix or postfix <VBScript>

I have a one Big File, In which I need to replace one string from the another.
File is getting Generated from the Jenkins Build and to process that, its using VBscript.

Here is the Deal for me, I can simply replace the string like this,

Replace(str_Renamed, "Variables", "Variables_Base", 1, -1, 1)

but in the same file "variables" is also there with suffix and postfix, these particular string i need to skip from the replace.

does VBscript has any function which can be useful for above conditions.
I am also looking for the answers, If I would find anything for it. I will post here.

Are there other characters next to "Variables" when it is without the postfix/suffix, i.e. could you use a space or space characters to isolate the match.
e.g.
Replace(str_Renamed, " Variables ", " Variables_Base ", 1, -1, 1)

Thanks for the Reply, i did try the same way as you are suggesting but its not working.