I don't know how you are representing True/False in your worksheet. So the "<true-value>" in code below may be a single digit "1" or a Boolean value TRUE, or just plain text "true", so make the necessary adjustment in the conditional statement.
if ((<get-cell-value>) -eq <true-value>){
# enable user for Skype Enterprise Voice
}
else{
# enable use for Skype
# enable user for Skype Enterprise Voice
}