Dear Experts:

I got numbers in column C with the following Synthax (xxxxSpacexxx),
e.g.

0250 434 or
0748 314

All these expressions are located in Column C and the 'Space' should
be replaced with an 'Underscore'.
After the replacement the expressions should look like this: 0250_434
or 0748_314

Please note: There are other expressions in cells of column C, such as
192344 / 134374. But those spaces should not be replaced with the
underscore character.

I would like to run a macro for this problem.

Thank you very much in advance for your professional help.

Regards, Andreas