If someone says to me
您打算这么干吗?
I would assume they were asking me "what are you planning to do" but the 这么 is throwing me off, would it be more accurate to assume they were asking me "in what way are you planning to do it?"
A bit more context would be helpful, but you could be right, 这么 can be translated as 'so, this way, like that'
您打算这么干吗?
Did you mean to do that?
Did you mean to do it like that?
Do you intend to do this?
Are you going to do this?
你应该这么做.
This is how you do it.
That's what you should do.
您打算这么干吗?
The English equivalence should be "Are you sure you want to do this thing in this way?" Or are you going to do it in this way?
When someone says that sentence, he knows you might do it in some way and he is trying to confirm about it. Basically, he is not asking whether you would do it or not, but you would do it in the way (you might have planned originally or you appear you tend to be )
这么: in this way