I have a string in an Excel cell. 

Each row represents a sentence. This string represents a positive and negative score for a word in a sentence.

Sentences can be of any length, e.g.

> 
> joy: pos=0.37 neg=0.0, honest: pos=0.4 neg=0.0, pick: pos=0.0 neg=0.0  
> 
>  hello: pos=0.0 neg=0.0, ok: pos=0.0 neg=0.0
> 
> 
> 

I want to calculate the total positive and negatives in the cell.

Without splitting the string up with the text to columns feature in Excel, I don't know a possible way to do this with a formula. 

An example of the output in this case would be:

> 
> pos=0.77 neg=0.0  
> 
>  pos=0.0 neg=0.0
> 
> 
> 

Any ideas?