How to replace just the first found space with tab for all lines in a variable?

[Keith Clarke]

Hi folks,
A simple requirement but I'm struggling with getting the structure and syntax needed to replace only the first space character in each line of a variable with a tab.

I have a field of label-value pairs - and some of the values contain spaces. This creates problems if I attempt a blanket approach of 'replace space in tVariable' with tab. 

So, I tried iterating through each tLine of tVariable but get a runtime error with 'replace space 1 in line tline with tab'. So, I'm guessing that 'space' can't be used to set chunk expression scope.

So, within each line, I'm iterating at character-level, with 'repeat for each character tChar in the line, if tChar is space then...

I've tried 'replace tChar with tab' and 'add tab after tChar' and then 'delete tChar' but I get errors - probably because I'm trying to delete the reference variable(?)

I'm sure there is a nice efficient way to do this, so any advice on structure, syntax or command usage would be greatly appreciated.
Best,
Keith..