Placeholder for numeric values in page filter

[Fox5]

Hi everyone
I assume my problem is simple to solve. Unfortunately, I did not find an answer by googleing it. I would be happy if you could help.

My table contains Data such as U1, U2, U3, U4, UK, UA etc. On the report page, wher I display the visuals, I need to filter the Data that contains the Us followed by a numer. So, the only data shown in the report's visuals should be U1, U2, U3, U4, while UK, UA are excluded on the visuals. Therefore, I want to use the filter function for the visual stating "begins with".

However, I don't know the placeholder for numbers. In Access, for example, I could filter my data using "begins with U#" (# being the placeholder for numeric values). This doesn't work in Power BI. I have tried to use "?" or "*" as placeholders for numeric values (i.e. U? or U*). This didn't do the trick.
Does anyone of you know what placeholder I need to use? Help is much appreciated.

[vanessafvg]

have you tried to use the search function in dax?

example 

= SEARCH("U",[fieldname])

here is a good video to explain how it is used

https://www.youtube.com/watch?v=PXdLFfhD2Cc

[Fox5 · Accepted solution]

Hi vanessafvg

Thanks for your reply. I didn't use your suggestion to solve my problem. Instead, I added a conditional column to my table (if then else) as a wor around. This solution is not perfect but it does the trick for now.